Campodesmidae, Cook, 1896

The Campodesmidae View in CoL

is monogeneric, with all 7–8 species of the single accepted genus Campodesmus Cook, 1896 , from tropical West Africa.These species are mediumsized (28–38 mm long), dark, with more or less strongly tuberculate metaterga and modestly deflexed paraterga, so that the usually dentate lateral edge of paraterga is nearly at the same level as the sterna ( Schiøtz 1966). The modestly enlarged paratergum 2 is devoid of any special structures except a rather shallow caudolateral emargination for the accomodation of the anterolateral parts of the moderately deflexed subsequent paraterga. This structure suggests incomplete or imperfect volvation ( Figs 8, 9 View Figs 1–11 ), and also implies a typical pattern of overlap. Direct observations confirm enrolment into a partial coil, a flattened oblate spheroid, rather than a true ball (Hoffman 1982 b).

The telson is ‘polydesmoid’ in the sense that it is typical of non-volvatory Polydesmida (cf. Hoffman 1982 b), i.e. fully exposed from above, with normal, large paraprocts (= anal valves) and a considerable hypoproct (= subanal scale), though the epiproct is strongly flattened and somewhat tuberculate. Nothing can be gained from available literature, as to opposite which body segment the telson of a completely coiled animal might rest. Yet, during the volvation, which can certainly be regarded as imperfect, especially when the collum and subsequent terga are armed with conspicuous tubercles, the flattened epiproct may be assumed to reach only as far as the collum or at most another of the few anteriormost terga.

Among the characters of Campodesmidae that attest to the group’s chelodesmidean stock, the gonopod structure is the most basic (Hoffman 1980 1982 b). This involves a large, transversely oval gonopod aperture containing elongate, subcylindrical coxae, loosely connected by a membrane, each coxa with a normal cannula; an elongate telopodite coiled distally, with a more or less strong protuberance medially at the base of the femorite ( Figs 10, 11 View Figs 1–11 ).

The pore formula is incomplete, with ozopores only present on paraterga 5 and 7. The rough metaterga are often covered with a soil crust, and the cuticle is finely granular. Antennomere 5 is longer than antennomere 6. The male coxa 2 bears a considerable distomedian process carrying the gonopore orifice; this trait is generally characteristic of the suborder Chelodesmidea . Further structural details of the family can be found in Schiøtz (1966) and Hoffman (1982 b).

Interestingly, tergum 2 in some congeners seems somewhat more incrassate than in others, e.g. Campodesmus dilobatus ( Schiøtz, 1966) ( Fig. 8 View Figs 1–11 ).

The affinities of Campodesmidae within the Chelodesmidea are not entirely clear. According to Hoffman (1982 b), not only Sphaeriodesmidae and Holistophallidae (cf. Hoffman 1980), but also Campodesmidae can be assigned to the superfamily Sphaeriodesmoidea .