REPORT ON THE STOMATOPODA. 85 



in the older larvae. The inner spine of the prolongation from the basal joint of the 

 uropod is much longer than the outer one, and it has a rounded lobe on its outer edge. 

 The exopodite is armed on its outer edge with five or six marginal spines. The eyes 

 are pear-shaped and the stalks very long. The mouth in old larva? is under the posterior 

 fourth of the carapace ; the postero-lateral angles of all the abdominal somites are i^ro- 

 longed into acute spines, and the dactylus of the raptorial claw shows traces of five 

 marginal spines. 



Alima gracilis is one of the best known and widely distributed Stomatopod larvae, 

 and any naturalist who has the good fortune to be becahned in tropical waters should 

 be able to determine the adult to which it belongs without difficulty, as the older 

 Stomatopod larvae thrive and moult in small aquaria. The very close resemblance 

 between it and the Alima from which Faxon reared a young Squilla empusa shows 

 beyond doubt that the adult is one of the highly specialized carinate Snuillee, and 

 its wide distribution indicates that the adult also is very widely distributed. The 

 most striking tliflfercnce between it and other Alimw is the great elongation which 

 takes place in the telson dui-ing the latest stages. The late appearance of tliis 

 character indicates that it is shared by the adult, and as there is no known 

 species with a long narrow telson, and as it is hardly possible that an animal which 

 must be one of the largest and most widely distributed of the Stomatopods, should 

 have^ escaped discovery if it were littoral in its habits, it is probable that Alima 

 gracilis is the larva of an unknown, deep-water Squilla, with an elongated telson and a 

 long raptorial claw. 



The smallest larva in the series from St. Vincent (No. 1) measures 5xVo mm. from 

 the tip of the rostrum to the middle line of the telson ; the second (No. 2, PI. IV. fio-. 4) 

 measures 61V0 mm., the thii-d (No. 3, PI. V. % 3) 9xV„^ mm., the fourth (No. 4, Pl^'lV. 

 fig. 5) IItIjV mm., the fifth (No. 5, PL IV. fig. 6) 17 f-^^ mm., and the sixth' (No- 6, 

 PI. VI. fig. 3) 42x^3^, or a little less than Claus' larva,' which is a little less than 52 

 mm. long. This large larva is weU known and widely distributed, and the Challenger 

 collection contains numerous specimens from St. Vincent, the west coast of Africa, the 

 Central Pacific, and the vicinity of Cape York. 



The youngest larva (No. 1) of the table was not figured as there is no difi-ercnce, 

 except in size, between it and No. 2, wliich is shown in PI. IV. fio-. 4. hi 

 this larva all the somites of the hind body, except the fifth and sixth abdominal, are 

 distinct, and the outUne of the fifth is indicated. The appendages of the sixth 

 abdominal are cntii-cly absent, those of the fifth are rudimentary bilobed pouches, while 

 the first four are well developed and functional, with a very long basal joint, a'ud an 

 appendix interna on the endopodite. 



There are no traces of appendages on the last six thoracic somites, and the thiixl, 



1 Metamorpliose der Sqiiillideii, pi. viii. fig. 35. 



