REPORT ON THE STOMATOPODA. 
17 
and he gives at length, on p. 154, his reasons for regarding Alima as the young of 
Lysiosquilla. It is true that he regards Lysiosquilla as a branch from the Squilla stem, 
and that in this sense he does hold that Alima is a Squilla larva, but I suppose no one 
would now regard Lysiosquilla as a Squilla. 
A comparison of these larvae with each other indicates that they are all derived from a 
primitive larval type which was hatched from the egg as an Erichthoidina, and reached its 
final form by gradual growth, and an increase in the number of somites and appendages, 
without any sudden change or the retrograde development of any of its appendages. It 
was furnished with a deep carapace, which, however, was not folded inwards at its 
ventral edges, and it was probably armed with a number of secondary spines between 
the submedian and intermediate spines of the telson, and the edge of the carapace was 
probably serrated. The most primitive among the recent adult Stomatopoda might be 
expected to retain the most primitive larval type. We know of no fully grown larva 
which can safely be referred to the genus Protosquilla, but the primitive larva must 
have been very similar to what we should have if the Erichthoidina shown in figs. 1 
and 2 of PI. XII. were to grow up and acquire its full number of somites and append- 
ages, while the carapace and telson remained without change. The Gonerichthus larva 
(PI. XA r . figs. 1, 3, 6, 11) passes through an Erichthoidina stage, its appendages undergo 
no retrograde metamorphosis, the hind body is convex, the carapace is deep but not folded 
inwards, there are no secondary spines, or only one or two on the telson between the 
submedian and the intermediate, the primary spines of the telson are long, and the 
outer spine of the basal prolongation of the uropocl is very much longer than the inner, 
and no specimens have ever been found with marginal spines on the edge of the long 
slender clactyle. The last four characteristics are also characteristics of the adult 
Gonodactylus. 
In Pseudericlithus (PI. XII. fig. 6) the carapace is deep and very slightly infolded 
along its lateral edges, the hind body is convex, the dactyle of the raptorial claw of the 
older larvae sometimes show traces of marginal spines, the outer spine of the uropod is very 
much longer than the inner, and the primary marginal spines of the telson are very 
long, the submedians are tipped with movable spinules, and there are only one or two 
secondary spines between the submedian and the intermediate. None of these character- 
istics are absolutely diagnostic of the genus Pseudosquilla, but as all except the last are 
true of the adults of this genus, it is probable that all these larvae are Pseudosquilla, 
like the one the history of which has been traced by Claus. If this larva hatches as an 
Erichthoidina it must undergo retrograde metamorphosis, since the younger larvae have 
no appendages on the third and fourth or fifth thoracic somites. 
In Erichthalima 1 the carapace is deep, and its lateral edges are infolded over the 
ventral surface, and serrated, the hind body is flat, the telson is wider than long, there 
1 Claus, Metamorphose der Squilliden, fig. 14. 
(ZOOL. CHALL. EXP. PART XLV. 1886.) 
Yy 3 ■ 
