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 larvse with each other indicates that they are all derived from a 

 primitive larval type which was hatched from the egg as an Erichthoidiiut, 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 \vith 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 fuUy grown larva 

 which can safely be referred to the genus Protosquilla, but the primitive larva must 

 have been ^'ery 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 Goiierichthus larva 

 (PI. XV. 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 telsou are long, and the 

 outer spine of the basal prolongation of the uropod is very much longer than the inner, 

 and no specimens have ever been found with marginal spines on the edge of the long 

 slender dactyle. The last four characteristics are also characteristics of the adult 

 Gonodactylus. 



In Pseuderichthus (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^ the carapace is deep, and its lateral edges are infolded over the 

 ventral surfjice, and serrated, the hind body is flat, the telson is wider than long, there 



' Clans, Metamorphose der Squilliden, fig. 14. 

 (zooL. CHALL. EXP. — PAr.T xLv. — 1886.) Yy 3 



