Cumacea: 24. Nannastacidae, 3. Nannastacus 



171 



4. N. minor Calm. 1911 N. m., Caiman ia: Tr. zool. Soc. London, tJ. 18iv 

 p. 341, 357 t. 34 f. 1—3 | 1912 N. m., T. Stebbing in: Ann. S. Afr. Mus.. v. lOv p. 164. 



Like Paranannastaciis reptans (p. 167), but dorsal surface of carapace 

 less arched, and branchial regions less inflated, antenna 1 with 3*^ segment 

 shorter than 2°^ peraeopods 1, 2, with well developed exopods, 2n<i pair with 

 2'^'^ joint inflated, L. 9 1-3 mm. d unknown. 



Gulf of Siam, depth 2 m. 



5. N. agnatus Calm. 1911 N. a., Caiman in: Tr. zool. Soc. London, u 18iv 

 p. 341, 360 t.34 f. 12, 13 j 1912 N. a., T. Stebbing in: Ann. S. Afr. Mus., u lOv p. 164. 



Like Paranannastams tanhis (p. 168), but telsonic segment shorter, 

 peraeopods 1, 2, with well developed exopods, 2"*^ joint of P* pair a little 

 shorter. 2''^ joint of 2''^ pair a little longer, hinder pairs slightly stouter and 

 shorter. L. Q 1-3 mm. d unknown. 



Gulf of Siam, depths between 9 and 28 m. 



6. N. lepturus Calm. 1911 N. l, Caiman in: Tr. 

 zool. Soc. London, ». 18iv p. 341, 352 t. 33 f. 1— 3. 



Pseudorostral lobes short, truncate, antero- 

 lateral margin shallowly concave, lower corner 

 rounded. Carapace slightly compressed, dorsal line 

 a little convex. Pedigerous segment 1 distinct, 

 side-plates of the following segments little expanded 

 laterally. Pleon segments each with well marked 

 lateral "groove, 5^^ twice as long as the truncate 

 telsonic segment. Antenna 1, 2'i*^ joint with sub- 

 distal process not reaching beyond the apex, each 

 flagellum 2-jointed, accessory a little shorter than 

 pt joint of principal. Peduncle of uropods about 

 twice as long as the endopod, which has 7 spines 

 on the medial margin; exopod about four-fifths 

 as long as endopod, but with a much longer apical 

 spine. L. d 2 mm. g unknown. 



Suez. 



7. N. longirostris 0. Sars 1879 iV. /., G. 0. Sars 

 in: Arch. Naturv. Kristian., vA p. 119 t. 58, 59 | 1905 N. 

 i. Caiman in: Siboga-Exp., nr. 36 p. 15 | 1911 N. l, 

 Caiman in: Tr. zool. Soc. London, t. l&iv p. 352. 



A slender form, integument thin, setulose 

 especially in 9 . Pseudorostral lobes strongly pro- 

 duced, horizontal, with divergent apices which are 

 serrate and setose, antero -lateral margin concave, 

 lower corner little produced, acute and bidentate 

 in 9, rounded in d. Carapace depressed along 

 the middle, in profile nearly horizontal, till it bends 

 down to the long pseudorostral lobes. Pedigerous 

 segment 1 short but distinct. Eyes wide apart, 

 each with 3 corneal lenses, larger in d than 

 in 9. Antenna 1, 3^ joint longer than 2^^, 

 nearly as long as l^S accessory flagellum 2-jointed. Masilliped 1, exopods 

 forming two clearly separated very narrow tubes, apically truncate, far- 



Fig. 116. 

 N. longirostris (J) Sars. 



