EEPOET OX 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 exopoclite is armed on its outer edge vcith five or six marginal spines. The eyes 
are pear-shaped and the stalks very long. The mouth in old larvae is under the posterior 
fourth of the carapace ; the postero-lateral angles of all the abdominal somites are pro- 
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 becalmed in tropical waters should 
be able to determine the adult to which it belongs without d iffi culty, 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 Squillae, and 
its wide distribution indicates that the adult also is very widely distributed. The 
most striking difference between it and other Alimas is the great elongation which 
takes place in the telson during the latest stages. The late appearance of this 
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 Alimct 
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 mm. from 
the tip of the rostrum to the middle line of the telson ; the second (No. 2, PI. IV. fig. 4) 
measures 6 T Vo mm., the third (No. 3, PI. V. fig. 3) 9^^ mm., the fourth (No. 4, PI. IV. 
fig. 5) ll^(j mm., the fifth (No. 5, PL IV. fig. 6) 17 x ^, mm., and the sixth (No. 6, 
PI. VI. fig. 3) 42-jVb) or a little less than Claus’ larva, 1 which is a little less than 52 
mm. long. This large larva is well 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 difference, 
except in size, between it and No. 2, which is shown in PI. IV. fig. 4. In 
this larva all the somites of the hind body, except the fifth and sixth abdominal, are 
distinct, and the outline of the fifth is indicated. The appendages of the sixth 
abdominal are entirely absent, those of the fifth are rudimentary bilobed pouches, while 
the first four are well developed and functional, with a very long basal joint, and an 
appendix interna on the endopodite. 
There are no traces of appendages on the last six thoracic somites, and the third, 
1 Metamorphose cler Sqiiilliclen, pi. viii. fig. 35. 
