SCHIZOCUMA AND STYLOPTOCUMA 



153 



also with a terminal, long, curved acuminate seta. Pereopod 5 (Fig. 

 4 G), basis as long as half of entire pereopod, carpus about 2 times 

 longer than propodus. Uropod (Fig. 4 H), peduncle shorter than in 

 female (2:1), 2 times longer than its rami, exopod as long as 

 endopod, with a long terminal seta, endopod with a subterminal long 

 simple seta and a terminal acuminate seta. 



Remarks. It does not seem possible to establish a neotype for the 

 species because the specimens from the British collection, although 

 from the same deep western Atlantic, are far (7° 58' S 34° 17' W) 

 from the type locality (27° 7' N 77° 08' W). 



Key for the identification of Schizocuma species 



1 Spines on carapace and eye lobe 2 



- Spines on carapace or on eye lobe 4 



2 Dorsal spines on the whole carapace 3 



Dorsal spines only on the posterior part of carapace 



S. molossa (Zimmer, 1913) 



3 Double rows of spines on carapace S. spinosum (Jones. 1984) 



- Single row of spines on carapace S. calmani (Stebbing, 1912) 



4 Spines only on eye lobe S. spinoculatum (Jones, 1984) 



- Spines only on carapace S. vemae Bacescu, 1972 



Genus STYLOPTOCUMA Bacescu & Muradian, 1974 



Styloptocuma Bacescu & Muradian, 1974: 74-75. 



Cumella Ledoyer, 1983: 77. 



Cumella Jones, 1984: 210-21 1. 



Cumella (Styloptocuma) Watling, 1991: 752 



Styloptocuma Bacescu, 1992: 262-265. 



Styloptocuma Holthuis, 1992: 264. 



Cumella Ledoyer, 1997: 869 - 876. 



Type species. S. antipai Bacescu & Muradian, 1974. 



DIAGNOSIS. Very elongate cumacean, with numerous spines on 

 entire body or only on carapace, long upturned pseudorostrum, long, 

 styliform eye lobe that could reach or even exceed the extremity of 

 pseudorostrum, without any traces of visual elements. Antenna 1 

 with a very long basal peduncle article (longer than half of pedun- 

 cle), second article with a tubercle, main flagellum with two long 

 articles, accessory flagellum with two articles, shorter than the first 

 article of main flagellum. Pars incisiva of mandible with 4 teeth, 

 lacinia mobilis with 4 (rarely 3) teeth, long stiff setae between 

 lacinia mobilis and robust pars molaris (without any tubercles). 

 Maxilla 1 with robust acuminate setae on protopod, palp with 2 

 filaments. Maxilla 2 with endites, possibly with a row of fine, small 

 setae between the outer margin of protopod and endites. Maxilliped 

 1 with basis never exceeding extremity of merus, carpus with hand- 

 like setae on outer margin, long propodus and rounded dactylus. 

 Maxilliped 2 with long and slender basis, propodus with two plumose 

 setae on distal outer corner, dactylus with terminal setae. Maxilliped 

 3 without inner process of basis, propodus longest article excepting 

 basis, dactylus with terminal claws or setae. Pereopods and uropods 

 very slender. Number of exopods - 3 in female, 5 in male. 



Gender. Neuter. 



ADDITIONAL SPECIES. S. aculeatum (Jones, 1984), S. acuminatum 

 (Jones, 1984), S. angustatum (Jones, 1984), S. concinnum (Jones, 

 1984), S. bishopi (Jones, 1984), S. cristatum (Jones, 1984), 5. dayae 



(Jones, 1984), 5. echinatum (Jones, 1984), S. egregium (Hansen, 

 1 920), S. erectum( Jones, 1 984), S. extans (Jones, 1984), S. formosum 

 (Jones, 1984), S. gracillimum (Caiman, 1905), S. inermis (Ledoyer, 

 1997), S. longisipho (Jones, 1984), S. subductum (Jones, 1984). 



REMARKS. Jones (1984) considered Styloptocuma to be a syno- 

 nym of Cumella because there did not seem to be any characters that 

 could be used to separate the genus (pseudorostrum, eye lobe, form 

 of body, antennule, pereopods and uropods). The absence of 

 mouthparts, especially maxilliped 1 , from the descriptions, and no 

 importance accorded to the tubercle on the antennule, also caused 

 Ledoyer (1983, 1997) to adopt Jones' view. In his revision of some 

 genera of nannastacids based on earlier descriptions, Watling 1991 

 concluded that Styloptocuma could be considered a subgenus of 

 Cumella. Holthuis (1992) discussed only the designation of the type 

 species of this genus and accepted the concept of Styloptocuma in 

 Bacescu & Muradian (1974) without any further comment. 



Styloptocuma possesses a mixture of characters that unite it with 

 most of the Cumella group - non-separated pseudorostral lobes, a 

 unique eye lobe, form of carapace, lacinia mobilis of mandible with 

 3 teeth, propodus of maxilliped 2 with setae, thin pereopods, long 

 uropods; and to the Nannastacus group - antenna 1 with tubercle, 

 mandible with 4 teeth on pars incisiva and lacinia mobilis, long, 

 rounded dactylus of maxilliped 1. Maxilla 2 has features of both 

 groups (the transeverse row of setules on the protopod is character- 

 istic for the Nannastacus group; absent in Cumella). This genus 

 seems to link these groups and therefore has a unique set of characters. 



Styloptocuma acuminatum (Jones, 1 984) 



Figs 5,6 



Cumella acuminata Jones, 1984: 220-221. 



Cumella (Styloptocuma) acuminata Watling, 1991: 752. 



Styloptocuma acuminatum Bacescu, 1992: 262. 



Description. A brief description of the distinctive characters of 

 the immature male not mentioned by Jones is given. Antenna 2 as in 

 Fig. 5 B. Maxilliped 3 (Fig. 5 C) has a longer basis and dactylar claw 

 than in the female. Pereopod 1 (Fig. 5 D) with an acuminate seta on 

 outer distal corner of basis. Pereopod 2 (Fig. 5 E) with teeth on outer 

 margin of basis and a shorter dactylus (shorter than carpus). Pereopods 

 3 and 4 (Fig. 5 F, G) with exopods, carpus longest article of pereopod 

 excepting basis, dactylus with a long curved terminal seta. Pereopod 

 5 (Fig. 5 H) with the shortest basis of all pereopods, carpus shorter 

 than in pairs 3 and 4. Uropod (Fig. 5 I) with peduncle 1 .2 longer than 

 the last pleonite and 1.8 times longer than its rami; subequal rami, 

 exopod with a terminal short acuminate seta, endopod with 5 slender 

 acuminate setae on inner margin and a short terminal robust acumi- 

 nate seta. 



To the description of female in Jones ( 1 984) the following details 

 are added: Antenna 1 (Fig. 5 J, K) with a tubercle on the 2 nd article 

 of the peduncle. Mandible (Fig. 5 L), pars incisiva with 4 teeth, 

 lacinia mobilis with 4 teeth (one of them very small), truncated pars 

 molaris. Maxilla 1 (Fig. 6 A) with robust acuminate setae on 

 protopod and palp with 2 filaments, the longest being backwardly 

 setulated in its proximal half. Maxilla 2 (Fig. 6 B) without a row of 

 fine, small setae between endites and outer margin of protopod. 

 Maxilliped 1 (Fig. 6 C) with a bifid robust acuminate seta on endite 

 of basis, carpus with hand-like flattened setae with 6 denticles, 

 dactylus smaller than propodus, enlarged, with excavated distal 

 margin. Maxilliped 2 (Fig. 6 D), slender basis, carpus longest article 

 excepting basis, propodus with plumose setae, dactylus with a 

 curved claw. Maxilliped 3 (Fig. 6 E), basis without inner process, 

 dactylus with terminal setae. Pereopod 3 (Fig. 6 H), with slender 



