THE GENUS ERETMOCAR IS 



375 



without exopod, long and slender. Leg 5 slender, a little shorter than leg 4. Pleopods 



long and slender. 



I have also two specimens from St. 1575 (18° 32' S, 4i°35'E) which agree in all 



respects with this description, but in which the antennal flagellum is retained. This 



flagellum is an enormously long, unsegmented rod, profusely covered with spicules. In 



one of the specimens the body is 9 mm. long and the flagellum 31 mm., though a little 



broken at the end. 



Key to the larvae described 



1. Abdominal somite 5 with pair of dorsal spines ... ... R.S.I 



Without these spines 



2. Leg 5 not larger than leg 4 

 Leg 5 distinctly larger ... 



3. Eyestalk of two segments 

 Eyestalk not divided 



4. Abdominal somite 3 with dorsal spine 



Without this spine 



5. Carapace with dorsal spine strongly procurved 

 This spine not procurved 



6. Eyestalk with spine 

 Without spine 



7. Eye and stalk more than half length of body ... 

 Much less than half 



8. Eye and stalk less than one-third length of body ; leg 4 propod dilated 

 Eye and stalk more than one-third body 



9. Supra-orbital spines present 

 Absent 



10. Eyestalk longer than eye, together nearly half body ... 



Eye and stalk about equal; together about one-third length of body 



3 



4 



A. VI {E. dolicJiops Ortmann) 

 A. VII 



A. V (£■. corniger Bate) 



5 



B.R. II 



6 



A.I 



7 



B.R. Ill 



A. IV 



... 9 



10 



R.S. II 



A. II 



A. Ill 



DISCUSSION 



I have described here twelve forms of " Eretmocaris" larvae, and an endeavour must 

 be made to determine whether any of them represent distinct generic types. One of 

 them (R.S. II) can be quite certainly identified as belonging to Lysmata, and this larva 

 agrees so closely with that of L. seticaiidata that the presumption is justified that any 

 considerable departure from that type must represent a distinct genus. The characters 

 of Lysmata, as founded on these two forms, are: 



(i) Rostrum short, with few dorsal teeth. 



(2) Carapace with antennal and pterygostomial spines, and dorsal tooth. (With or without 

 supra-orbital spine?) 



(3) Abdominal somites without spines, and with rounded pleura. 



(4) Eyes carried on long, but not excessively long, stalks. 



(5) Endopod of antenna in stages I and II a slender rod, with one long seta; reduced to a short 

 stump in stages III and IV. 



(6) Leg 4 with exopod; propod not dilated. 



(7) Legs 5 fully developed in stage II when legs 3 and 4 are rudimentary. 



(8) Leg 5 enormously large, with dilated propod. 



