Caraiboscia Vandel, 1968

Leistikow, Andreas, 2001, A new species of Caraiboscia Vandel, 1968 from South America, and a type species for Colombophiloscia gen. n. (Crustacea: Oniscidea: Crinocheta), Journal of Natural History 35 (4), pp. 497-514 : 498-499

Genus Caraiboscia Vandel, 1968

Diagnosis. Pigmentless, with rostrally bent, specialized tricorn-like setae on dorsum and cephalothorax. Cephalothorax without linea frontalis, very faint linea supra-antennalis; three to four individualized ommatidia laterally. Antennula with row of aesthetascs medially, antenna stout with three-articulate ¯agellum and long apical organ.

Mandibles with simple molar penicil, maxillula with eight teeth, only one of them cleft, maxilla with setose lobes, lateral lobe half as broad as medial one, maxilliped with sulcus lateralis, endite bearing scales and knob-like penicil rostrally.

Pereopods with transverse antenna-groomin g brush on carpus 1, ornamental sensory spine with double-fringed apex, dactylar seta simple or only slightly plumose, inner claw of dactylus short in pereopods 5 to 7 and long in pereopods 1 to 4, coxal plates with gland pores in pereopod 1, short nodulus lateralis present. Pleopods with rhomboid exopodites, without particular respiratory areas. Uropod with grooved protopodite and endopodite inserting proximally of exopodite. Genital papilla with truncate terminal spatula surpassing ventral shield.

Type species. Caraiboscia microphthalma Vandel, 1968 (by monotypy and original designation).

Number of species. Two species, both from the Neotropics.

Distribution. Northern South America from Guyana to Ecuador.

Remarks. The genus Caraiboscia is a pigmentless taxon with reduced compound eyes and lives`un mode de vie humicole ou endogeÂ’ ( Vandel, 1968). The generic diagnosis comprises a set of plesiomorphies. Autapomorphies of Caraiboscia are:

E drop-like shape of the male pleopod 1 exopodite [pleopod 1 expodite subtriangular];

E small bulbs at the apex of pleopod 1 endopodite[apex of pleopod 1 endopodites smooth];

E saw-like structure on male pleopod 2 endopodite [pleopod 2 endopodite smooth];

E linea supra-antennalis reduced [linea supra-antennalis present];

E profrons with two prominent depressions [depressions on profrons shallow];

E lateral endite with 41 5 teeth, only one cleft [lateral endite with 41 6 teeth, ®ve of inner set cleft].

The leaēt tricorns are slightly derived in Caraiboscia compared to Colombophiloscia , which is described below. The leaf-like cuticle is fused with the supporting scale of the tricorn itself and the setae are bent anteriorly.

Very speci®c characters of Caraiboscia are the shape of the male pleopod 1 exopodite and the saw-like structure on the male pleopod 2 endopodite. These are complex characters which support the monophyl y of the genus whereas the reduction of the linea supra-antennalis itself is rather susceptible to convergence. This latter character has to be seen with the diOEerentiation of the cephalothorax, with respect to the modi®cation of the profrons and its depressions.

In contrast to the statement of Vandel (1968), the noduli laterales are clearly discernible and are all inserted at the same distance to the lateral margin of the coxal plates.

After cautious re-examination of Phalloniscus langi (van Name, 1936) and Phalloniscus pearsei (van Name, 1936) the genus might be enlarged by these species from Guyana. Some material collected on Trinidad at Navet Dam Lake by H. J. Just, deposited in the Zoological Museum of Copenhagen, belongs to this genus, too. The only male is too damaged to allow speci®c recognition.