Vemacumella, Petrescu, 2001

Petrescu, I., 2001, New deep-sea Nannastacidae (Crustacea, Cumacea) from the Eastern Pacifc collected by R. V.`Vema’, Journal of Natural History 35 (11), pp. 1657-1680 : 1675-1676

Vemacumella n. gen.

Type species. Vemacumella heardi n. sp.

Diagnosis. Ocular lobe strong, not reaching tip of pseudorostrum; antenna 1 with second article of peduncle with a tubercle, accessory agellum with three articles; pars incisiva of mandible with four teeth, lacinia mobilis with three teeth, pars molaris truncated, maxilla 1 with two laments; maxilla 2 with two endites, maxilliped 1 with enlarged dactylus; maxilliped 2 with plumose setae on carpus; uropodal exopod two articulated and endopod with one article.

Gender. Feminine.

Etymology. This genus bears the name of the oceanographic vessel ‘Vema’ which collected this cumacean material. The second part of the name refers to the genus Cumella Sars, 1865 , with which it shares some characters.

Remarks. This genus has several characters in common with Cumella : ocular lobe shorter than pseudorostrum, lacinia mobilis with three teeth, maxilla 1 with simple stout setae and two laments, maxilla 2 with two apical articles and small setae only on inner margin of protopod, maxilliped 2 with plumose setae on carpus, and maxilliped 3 with short outer process on basis. It diOEers from Cumella in having a tubercle on peduncle of antenna 1, pars incisiva of mandible with four teeth (no more than three teeth on Cumella ), an enlarged dactylus of maxilliped 1 (thin one in Cumella ). These characters are shared with Styloptocuma Bacescu and Muradian, 1974 and Nannastacus Bate, 1865 . Vemacumella n. gen. has an ocular lobe shorter than Styloptocuma (very important character for this genus, Petrescu, in press); Nannastacus has separated ocular lobes; accessory agellum of antenna 1 with three reduced articles with long sensory terminal setae (two articles in Styloptocuma and Cumella , more like Procampylaspis ). This new deep-sea genus could be considered more archaic than Styloptocuma , surviving in this isolated environment, and suggesting an evolutionary trend from Cumella to Styloptocuma .