Two new species, including one representing a new genus, of the West African millipede family Campodesmidae (Diplopoda: Polydesmida)

A new genus, Campodesmoides gen. nov., is described to only encompass C. corniger sp. nov., from Cameroon. This genus and species is distinguished from the few known species of the small western African family Campodesmidae, all currently in Campodesmus, by the much longer antennae and legs, the normal pore formula with ozopores borne on porosteles, and the suberect and distally twisted gonopod, coupled with peculiar horns on a few anterior postcollum segments. A new Campodesmus is also described, C. alobatus sp. nov., from Ivory Coast, which differs from congeners primarily in the lack of a dorsal/lateral lobe on the otherwise usual and strongly subcircular gonopod telopodite, albeit the latter is not directed mesad, but held subparallel to the main body axis.


Introduction
The small millipede family Campodesmidae is currently known to comprise "about eight species" from Liberia, Sierra Leone, Ghana, Ivory Coast and Nigeria (Hoffman 1980(Hoffman , 1982)), albeit Demange (1971) had considered and keyed only seven.All of them are assigned to the genus Campodesmus Cook, 1896, which is characterized by a dark medium-sized body (17-38 mm long) with more or less strongly tuberculate metaterga and only moderately declivous paranota (Schiøtz 1966).The modestly or even not enlarged paranota 2 suggest incomplete or imperfect volvation, i.e., enrollment into only a partial coil (Golovatch 2003).Ozopores are only present on paranota 5 and 7.The gonopod aperture is rather large, transversely oval, the edges at least partly being elevated and the gonopods almost fully exposed.
The gonocoxae are elongated subcylindrical, fused basally, at best poorly setose, concealed inside the aperture.The telopodites are long, strongly subcircular, directed anteromesally, crossing in situ, on the dorsal/lateral face usually with a prominent, variously shaped lobe (= prefemoral process) at the base of the telopodite.
Interestingly, the course of the seminal groove has never been traced and properly described in the literature (Hoffman 1951(Hoffman , 1982;;Schiøtz 1966;Demange 1971).Based on the available illustrations, however, the family and genus could additionally be characterized by the lack of a special solenomere to support at least the terminal part of the seminal groove.
The present paper records two new species of Campodesmidae: 1) a new Campodesmus from Ivory Coast, and 2) a second genus of the family, Campodesmoides gen.nov., a monotypic taxon from Cameroon.These two genera are markedly distinct from each other both in gonopod conformation and several somatic characters.

Material and methods
All material treated here derives from the collection of the Musée Royal de l'Afrique Centrale (MRAC), Tervuren, Belgium, with only one paratype shared with the holdings of the Zoological Museum of the Moscow State University (ZMUM), Moscow, Russia.The samples are stored in 70% ethanol.Specimens for scanning electron microscopy (SEM) were air-dried, mounted on aluminium stubs, coated with gold and studied using a JEOL JSM-6480LV scanning electron microscope.Photographs were taken with a Leica DFC 500 digital camera mounted on a Leica MZ16A stereo microscope.Images were processed with the Leica Application Suite software.

Diagnosis
Same as for Campodesmoides corniger sp.nov., due to monotypy of this genus.

Etymology
The name of this genus emphasizes the attribution of the new genus to the Campodesmidae which has been known so far by the single genus Campodesmus.Gender masculine.

Diagnosis
A species of Campodesmidae which differs from other species of the genus Campodesmus, the only hitherto recognized genus of Campodesmidae, by the long and only slightly clavate antennae, which reach behind segment 3 when stretched dorsally; the considerably longer legs which in the male are about 1.5 times as long as midbody height; the normal pore formula: 5, 7, 9, 10, 12, 13, 15-19, the ozopores being borne on conspicuous porosteles (versus reduced to 5, 7 without porosteles); the more dorsally situated paranota which are set at the upper ¼ of midbody height (versus about half of midbody height); the nearly flat sterna and the gonopod telopodites being suberect, in situ directed forward, not crossing mesally, each with a clearly twisted solenophore devoid of a distinct solenomere.

Etymology
To emphasize the high, vertical, paramedian horns present on metatergum 2, these growing increasingly small on metatergum 3 and, especially, 4; noun in apposition.

Description
Length of holotype c. 26 mm, width on midbody pro-and metazonae 2.5 and 5.0 mm, respectively.female paratypes 25-30 mm long, 2.5-3.6 and 3.6-5.0mm wide on pro-and metazonae, respectively.Coloration from light grey-brown (female) to blackish brown (male, female) (Fig. 1), darker specimens with brown to chocolate brown antennae and legs; tips of antennae, distal parts of paranota 5, 7, 9 and 13 together with their porosteles, as well as the remaining porosteles (male, female) or only all porosteles (female) yellowish to nearly pallid.
Head.Except for a bare and rather densely setose clypeolabral region, very densely microdenticulatemicrotuberculate-microgranulate, interantennal isthmus almost as broad as diameter of antennal socket (Fig. 2).Antennae long and only slightly clavate due to a somewhat higher antennomere 6, in situ reaching behind segment 3 when stretched dorsally; only antennomere 6 with a dorso-apical group of tiny bacilliform sensilla; in length, antennomere 6 > 2 > 3 = 5 > 1 > 7; apical segment with the usual four sensory cones.
Gonopod.Aperture transversely ovoid, large, its lateral and posterior edges slightly elevated, fully concealing gonocoxae and bases of telopodites.Gonopod coxites medium-sized, subcylindrical, fused at base to a small membranous sternal remnant, poorly setose distodorsally, including a pair of very closely placed, distalmost, particularly long setae.Cannulae slender, without peculiarities (Fig. 3A-B).Telopodites in situ directed forward, held subparallel to each other, suberect, not crossing each other mesally.Prefemoral (= densely setose) portion (pf) subcylindrical, very long and slender, untwisted, almost not enlarged towards an oblique apical cingulum (c) delimiting it from femorite, with a long, slightly curved, distodorsal process (pfp).Femorite clearly twisted, lamellar, about half as long as pf, forming a large, rounded, apical lobe = solenophore (sph) to protect a smaller, parabasal lobe (lo) carrying terminal part of seminal groove on its distal rib.Seminal groove first running fully on mesal side of pf, then moving laterad above c onto distal rib of lo to end at tip of lo (Fig. 3C-E).

Remark
This new genus and species extends the range of Campodesmidae to Cameroon in the east, the family also being recorded in that country for the first time.

Diagnosis
Differs from other members of the genus in the complete lack of a parabasal process/lobe on the gonopod telopodite which is not directed mesally, but held subparallel to the main body axis, coupled with much more numerous, nearly undifferentiated and low tubercles on metaterga and the presence of deeply incised and clearly separated antero-and caudolateral lobulations on the postcollum paranota.

Etymology
The name of this species emphasizes the absence of a dorsal/lateral parabasal process/lobe from the gonopod telopodite.

Description
Length of holotype c. 17 mm, width on midbody pro-and metazonae 1.7 and 3.6 mm, respectively.Paratypes (males) also c. 17 mm long, width on midbody pro-and metazonae 1.6-1.7 and 3.0 mm, respectively.Coloration from light grey-brown to brown (Fig. 4); clypeolabral region, antennae, prozonae, venter, legs and tip of epiproct pallid to light yellow; stricture as brown as metazonae.Head.Densely setose, clypeolabral region smooth, remaining parts densely microdenticulatemicrogranulate, interantennal isthmus c. 1.5 times as broad as diameter of antennal socket.Antennae short and strongly clavate, C-shaped, antennomere 5 largest and longest, but only a little larger than 6 th , both with a dorso-apical group of tiny bacilliform sensilla; apical segment with usual four sensory cones (Figs 4,5G).
Body.With 20 segments (male).In width, head << collum = segment 2 < 3 < 4 < 5-17; thereafter body rapidly tapering towards telson.Collum transversely ellipsoid, subflabellate, covering most of head from above, dorsal surface rather regularly and densely tuberculate, with about 4-5 transverse rows of round, setigerous, undifferentiated tubercles lying between a moderately crenulate/lobulate and regularly rounded anterior margin and a clearly ribbed and almost straight caudal edge; small, but discernible caudal paranota with a rather sharp lateral tooth (Figs 4, 5A, D, G).Prozonae smooth and poorly shining, stricture finely microgranulate; metazonae dull, densely tuberculate and microgranulate over entire surface; cerotegument well-developed, sometimes in places clothed with a crust of soil; dorsal surface usually with two regular, mixostictic (= not regularly longitudinal) transverse rows of normally similar round tubercles, much like on collum, lying between a fore row of denser and smaller knobs/tubercles behind stricture and a densely ribbed caudal edge represented by a flatter row of oblong tubercules (Fig. 5A-F).Paranota 2 not enlarged compared to following ones (Figs 4,5A).Postcollum paranota set rather low (at about half of midbody height, thus dorsum being very strongly convex), strongly declivous, continuing the outline of dorsum, but their tips not reaching level of venter (Fig. 5A-C, J); lateral margin of paranota usually 5-lobulate, laterals continuing into even more deeply lobulate caudo-and anterolaterals both at caudal and fore margin, respectively; caudo-and anterolateral lobulations continuing both caudal and fore rows of tubercles at base of paranota, respectively (Figs 4, 5A-I).Caudal corner of paranota increasingly strongly inclined caudad behind rear tergal margin only in segments 17-19 (Fig. 5C, F, I).Tergal setae very short and thin (Fig. 5A-L).Ozopores inconspicuous, opening flush on tergal surface at about midlength of paranota 5 and 7 off lateral margin.Pleurosternal carinae absent (Fig. 5G).Limbus microcrenulate, with microserrate tips of crenulations, these latter clearly separated from one another (Fig. 5M).Epiproct short, small, subtruncate, slightly flattened dorsoventrally, tuberculate dorsally, with a pair of rather large subapical papillae (Figs 4, 5C, F, I).Hypoproct nearly semi-circular with 1 + 1 caudal setae very distinctly separated and borne on minute knobs (Fig. 5I).Sterna.Broad, almost twice as broad as coxa length, with a very deep axial impression (Fig. 5G-I).Gonapophysis on male coxae 2 a small tubercle.Legs short, even in male about 0.9-1.0 times as long as midbody height, very slender; in length, femur > tarsus > prefemur > postfemur = tibia = coxa; claw very small, very slightly curved; ventral surface of tarsi densely setose, but forming no brushes.
Gonopod.Aperture transversely ovoid, large, its lateral and posterior edges slightly elevated, fully concealing gonocoxae and bases of telopodites.Gonopod coxites medium-sized, subcylindrical, fused at base to a small membranous sternal remnant, each with only one long distodorsal seta (Fig. 6A, B).Cannulae long and slender, without peculiarities.Telopodites rather regularly curved caudad, in situ held subparallel to each other, subcircular, long, slender and quite simple (Fig. 6).Prefemoral (= densely setose) portion (pf) subcylindrical, rather long, totally devoid of outgrowths.Femorite (fe) with a small parabasal denticle (d) on ventral face and a series of inconspicuous folds (f) on opposite side.Seminal groove (sg) running entirely on mesal side, terminating at about halfway along fe, at base of a small denticle (o), with neither a hairpad nor an accessory seminal chamber.Tip of fe slightly broadened and bifid (Fig. 6C).

Remarks
The species described above is the 8 th known species of Campodesmus which, despite the peculiarities referred to in the diagnosis, remains a rather typical congener.This is primarily evidenced by the gonopod conformation which shows long and subcircular telopodites.Such non-gonopod characters as low paranota, a reduced pore formula, short antennae and legs etc. also attest to the unequivocal assignment of this new species to Campodesmus (cf.Hoffman 1951;Schiøtz 1966;Demange 1971).
The clearly abbreviated seminal groove in C. alobatus sp.nov., which only extends to about the midlength of an untwisted gonopod femorite, invites comparisons with other congeners.Regrettably, no such information is available in the literature.Schiøtz (1966) attempted to group most of the species of Campodesmus, but more data are needed, including the course of the seminal groove, to reach more secure conclusions.