1913.] S. Kemp : Crustacea Stomatopoda of the Indo-P acific 



*spinosissimus, Pfeffer. tanensis (Fukuda) . 



spinoso-carinatus, Fukuda. trispinosus, Dana, 



stoliurus (Müller). tuberosus, Pocock. 



The species known from the Atlantic and Mediterranean and from the Pacific 

 Coast of America are separately listed at the end of this paper with a few of the more 

 important references and synonyms (p. 200). 



The exact relations of the Stomatopoda with other groups of Crustacea present 

 a difficult problem. The existing forms show a high degree of specialization coupled 

 with several features that at first sight seem primitive. Of the latter the most striking 

 is the freely movable ophthalmic and antennular somites, but this is now regarded 

 as a secondary character and must also be taken as evidence of specialization. 

 With the" views which Caiman has expressed on the affinities of the group I am in 

 entire agreement and his conclusion (1909, p. 331) that it seems most probable that 

 " the Stomatopoda are a lateral offshoot from the main stem of the Malacostraca, of 

 which, in the absence of connecting links, it is as yet impossible to determine the 

 exact relations," will, I believe, meet with general acceptance. 



The oldest known fossil Stomatopoda have been found in the Jurassic beds of the 

 Solenhof en and have been referred to the genus Sculda. Little information of the 

 really satisfactory nature is available concerning these forms; but there is, I believe, 

 enough to warrant the creation of a separate family for their reception (see p. 15). 

 The species are for the most part ornamented with an elaborate sculpture in no respect 

 less remarkable than that of some of the existing forms of Squilla and Gonodactylus , 

 though of an entirely different type, and it is clear that they also must have attained 

 a high degree of specialization. It is to be hoped that specimens will soon be found 

 which will provide satisfactory material for a study of the appendages. In parti- 

 cular, information regarding the form of the second thoracic appendage, which attains 

 such a monstrous development in the Squillidae, would be most valuable. This limb 

 has been found in an excellent state of preservation in fossil examples of Squilla, but 

 it has never been satisfactorily demonstrated in Sculda. Seeing that in the former 

 genus it appears to be well adapted for preservation in stratified rocks it is difficult, 

 on the view that it possesses a similar development, to explain its absence in the 

 latter. 



Species of Squilla have been obtained in the Cretaceous and in the London Clay 

 and other tertiary deposits, and in all structural details which have been studied they 

 appear to bear a close resemblance to existing representatives of the genus. 



Brooks held that the forms which he included under the genus Protosquilla (here 

 regarded merely as a section of Gonodactylus) were the most primitive that persist ; 

 but this view has been severely criticized by Hansen and is not now generally 

 accepted. My own observations lead me to conclude that it is among the species of 

 Squilla that the most primitive forms are to be sought ; but the precise relationships 

 of the several genera are by no means easily traced. 



The genera fall without difficulty into two groups, the one comprising Squilla, 



