90 THE VOYAGE OF H.M.S. CHALLENGER. 



the second abdominal somites. The lateral edge of the carapace has a few, five or six, 

 marginal spines, and a well marked dorsal spine. The postero-lateral angles of the abdo- 

 minal somites end in acute spines, and the inner and longer of the two basal spines of 

 the uropod has a rounded lobe on its outer edge close to its base. The carpal joint of 

 the raptorial claw is as much elongated as it is in Alima gracilis, although the telson is no 

 longer than its width. As the adult form is certainly a Squilla, closely related to Squilla 

 nepa and Squilla mantis, it does not seem necessary to give the larva a provisional name. 



Squilla {Alima), empusa. — In order to render the series of Alima larvae more 

 complete, I give two figures, a ventral and a side view (PI. I. figs. 4, 5), of a larva 

 which is smaller and probably one moult younger than any of those in the Challenger 

 collection. 



The drawings were made from the living larva, which is probably the larva of Squilla 

 empusa, and the same as the one Avliich is shown in Faxon's pi. vi. fig. 17. It is 3 "2 16 

 mm. long and the last six thoracic somites increase uniformly in length from in front 

 backwards, and have no traces of appendages ; the sixth abdominal somite is absent, and 

 the fifth very short and without aj^pendages. The telson is longer than wide, narrowed 

 anteriorly and posteriorly, and the four spines between the submediau and the inter- 

 mediate are nearly as large as the latter. The rostrum is short, and not quite as long as 

 the slightly divergent postero-lateral spines of the carapace, which is oval in outline and 

 nearly as wide in front as behind. It crosses the posterior end of the seventh thoracic 

 somite in the middle line, and the tips of the postero-lateral spines are about opposite the 

 middle of the third abdominal somite. The tip of the labrum is close to the anterior 

 end of the carapace, and the eye-stalks are short, less than half as long as the eyes. 



Alima hidens. — Claus has figured and described,^ under the provisional name Alima 

 bidens, an Alima larva which is of especial interest, as many of its organs, especially the 

 gUls and the dactyles of the raptorial claws, undergo much more complete development 

 during the larval life than is usually the case, and it therefore presents more data than 

 the ordinary larvae for establishing an identity with some one of the genera of adult 

 Stomatopods. 



Although Claus regarded it as the larva of some species of Lysiosquilla, I shall show 

 that Alima hidens must be referred to the genus Squilla, and there is, so far as I 

 am aware, no other Stomatopod larva which exhibit clearer evidences of relationship to a 

 definite adult genus. 



It is of course desirable that some one who has the opportunity should actually rear it, 

 and determine in this way the specific adult of which it is the larva, but in the absence 

 of this decisive proof the evidence that it is a Squilla could hardly be stronger than it 

 now is. 



Claus obtained only a single larva 26 mm. long from the Indian Ocean, and as this 



' Metamorphose der Squilliden. 



