Cumacea: 24. Nannastacidae, 3. Nannastacus 169 



( Uropods with peduncle at least twice as long as telsonic 

 ) segment — 7. 



\ Uropods with peduncle not nearly twice as long as telsonic 

 1 segment — 9. 



„ I Pseudorostrum short 6. N. lepturus 



\ Pseudorostrum long — 8. 



iPseudorostral lobes strongly produced with divergent 

 apices 7. N. longirostris 

 Pseudorostral lobes less strongly produced, the truncate 

 apices not divergent ■ . 8. N. braehydactylus 



f First five segments ot pleon with paired dorsal carinae — 10. 

 \ Pleon segments without paired dorsal carinae — ■ 11. 



( Pseudorostrum upturned, ridged 9. N". ossiani 



^^ \ Pseudorostrum horizontal, smooth 10. N. hanseni 



f Carapace smooth — 12. 



\ Carapace rough with hairs, granules, or spines — 13. 

 / Fifth peraeopod with fifth joint little longer than sixth 11. N. georgi 

 ^^ \ Fifth peraeopod with fifth joint much longer than sixth 12. N. pardus 



f Eyes not very wide apart 13. N". hirsutus 



\ Eyes wide apart — 14. 



f Carapace roughened with granules, without spines ... 14. N. brevicaudatus 



\ Carapace with spines — 15. 



IAntero-lateral angles of carapace serrate; uropods with 

 exopod about one-third as long as endopod . . . . 15. N. unguiculatus 

 Antero-lateral angles of carapace not serrate; uropod 

 with exopod nearly half as long as endopod . . .16. N. stebbingi 



1. N. zimmeri Calm. 1911 N. z., Caiman in: Tr. zool. Soc. London, r. 18iv 

 p. 341,352 t.33 f.4— 15. 



9. Pseudorostral lobes short, obliquely upturned, narrowly truncate, 

 meeting below but not above the branchial channel; antero-lateral margin 

 deeply concave, antero-lateral angle produced into a blunt, apically setose 

 spine. Carapace inflated behind, much naiTOwed in front, dorsal line convex, 

 a slight elevation at the rear bearing a small tubercle. Pedigerous segment 

 1 a narrow strip with expanded side-plates. Pledn without teeth or spines. 

 Maxilliped 3 without exopod, but with blunt distal process on 2''^ joint. 

 Peraeopods 1, 2, with exopods. Peduncle of uropods nearly one-third as 

 long as the endopod, which is over eight times the length of the exopod, 

 but has a shorter apical spine. A dark patch of pigment on each side of 

 the carapace anteriorly, and a baud encircling 5*^ segment of pleon. L. 1-5 mm. 

 d. Pseudorosti-al lobes short, blunt, meeting a short distance above 

 the branchial channel; antero-lateral margin deeply concave, angle rounded 

 and followed by a curved spine and some serration. Carapace with surface 

 minutely granular, not much narrowed in front, dorsal line nearly straight, 

 with depression between the inflated branchial regions. Pedigerous segment 

 1 scarcely visible, and its side-plates very small. Pleon with lateral groove 

 overhung by a serrated crest in each segment. Eyes dark, larger than in g , 

 and less wide apart. Antenna 1 has 2"^ joint produced distally into a naiTow 

 process tipped with plumose setae. Maxilliped 3 with well developed exopod, 

 2'*^ joint relatively longer than in 9. Peraeopod 5 with -5*^ and 7^*^ joints 

 long. Uropods with endopod about ten times as long as exopod. Colour 

 as in 9 and sometimes also bands on 3"^ and 4*^ pleon segments. L. 1-6 mm. 



Trincomali, Ceylon, surface. 



