LEPTOSTRACA, SCHIZOPODA AND STOMATOPODA. 177 



but the present Alima differs from A. bidens in having a well-marked postero-median 

 dorsal spine on the carapace. 



Three Alimce, captured in a trawl off Galle, do not seem to differ materially from 

 the above except in size. They measure 19 millims. in length, but are more advanced 

 in their development than the larva of 27 millims. described above. The uropods 

 extend very nearly to the intermediate spines of the telson and have traces of seven 

 spines on the outer edge of the external branch. The telson is about as long as broad, 

 and bears twelve submedian, ten intermediate, and a single lateral denticle on its 

 margins. Its shape is in substantial agreement with the 27-millims. larva described 

 above. 



Alimericlitlms unidens, LANCHESTER, 1902. Plate II., fig. 26. 



Locality: East of the Gallehogalle Bank, 16 to 30 fathoms, fine sand. Two 

 specimens, 12 millims. and 9 millims. long, from the eye to the telson. 



The largest of the Ceylon larvae is practically the same size as LANCHESTER'S type, 

 and appears to be at the same stage of development. I am able to confirm the fact, 

 established by LANCHESTER, that in some Alimerichthii at least the postero-lateral 

 angles of the abdominal segments end in acute spines, because both in the specimens 

 here referred to A. unidens, and also in another species described below, such spines 

 are distinctly present and well developed. As points not noticed by LANCHESTER, 

 it may be mentioned that the telson in both specimens has forty-four submedian 

 spinules and eight intermediate ones. There are eight spines on the outer uropod 

 of the large specimen, but only two on that of the smaller, a difference quite in 

 accordance with the difference in size. The dactylus of the raptorial claw (fig. 26) has 

 in both specimens one fully developed spine in addition to the terminal one and traces 

 of two others beneath the skin. A figure of the raptorial claw is given for comparison 

 with the other Alimerichthus described below. 



Distribution : Maldive and Laccadive Islands (LANCHESTER). This is the only 

 previous record for the species, the distribution of which is now extended to Ceylon. 



Alimerichthus a. Plate II., figs. 27 to 29. 



Locality: Cheval Paar, 7 fathoms. Two specimens, 9 millims. and 10 millims. 

 long from eye to telson. 



This larva differs chiefly from A. pyramidalis, LANCHESTER, and A. unidens, 

 LANCHESTER, the only two described species of this type of larva, in size, being 

 only 9 millims. long, but at a stage in its development rather later than either 

 A. pyramidalis at 16 millims. or A. unidens at 12 millims. It evidently belongs to a 

 smaller species of adult than either of the above two. A brief description may 

 enable the species to be recognised in any future collections. 



Carapace, (figs. 27 and 28) rather wide, leaving only one thoracic segment exposed, 

 exhibiting in lateral view the same pyramidal form already noticed by LANCHESTER 



13 A 



