REPORT ON THE STOMATOPODA, 65 



Genus Protosquilla, n. gen. (PI. XVI.). 



Diagnosis.— ^m^W Stomatopoda with the sixth abdominal somite more or less 

 completely fused with the telson ; the rostrum furnished with long acute median and 

 antcro-lateral spines ; the dactylus of the raptorial claw dilated at the base, and without 

 marginal spines, the eyes, antennary scales, and uropods small, and the hind body convex. 

 Ontogeny unknown. 



General Description and Remarks. — The following small but very interesting and 

 remarkable Stomatopoda are very slightly known, and most of the species have, on account 

 of the absence of spines on the dilated dactylus of the raptorial claw, been placed by various 

 authors in Latreille's genus Gonodactylus, although they resemble each other in many 

 features which are also points of difference from Gonodactylus as weU as from all other 

 Stomatopoda. 



While it is also true that they differ greatly among themselves, it is not difficult to 

 discover a common type of structure which runs through them all, and which should find 

 its expression in our system of classification. I therefore place them in a distinct genus, 

 and as many of their distinctive characteristics, such as the small size of their antennary 

 scales and uropods, the great length of the acutely pointed rostrum, and the union of the 

 sixth abdominal somite with the telson, are points of resemblance to the Stomatopod 

 larva, I propose for the genus the name Protosquilla. This name is the more appropriate 

 inasmuch as all the other Stomatopoda present evidences of divergent descent from a 

 common stem form, which, like the living representatives of the genus Protosquilla, was 

 characterised by the small size of its eyes, antennary scales, and uropods. In this genus 

 the dactylus of the raptorial claw is dilated at the base, with microscopic serrations, but 

 no spines, on its inner margin ; the rostrum has a long slender acute median spine, and 

 one or more pairs of acute antero-lateral spines; the eyes are small and subcylindrical ; 

 the carapace is smooth and flat, with well-marked longitudinal sutures, but with the 

 transverse cervical suture obsolete ; the hind body is convex, without dorsal caringe on 

 the first four terga, with its posterior end curved downwards, and with the sixth 

 abdominal somite more or less completely fused with the telson. The telson and sixth 

 abdominal somite differ in texture from the general surface of the body, and are often 

 remarkably and elegantly ornamented ; the telson is usually wider than long, and its mar- 

 ginal spines are pushed backwards, and are either obsolete or else developed in a remarkable 

 manner. The eyes, antennary scales, and uropods are very small, and the prolongation 

 from the ventral surface of the basal joint of the uropod ends in two short stout spines. 



AU but three of the following species are known to exhibit all of these characteristics, 

 and while the published accounts of those three are so incomplete as to leave many points 

 in uncertainty, the close general resemblance between them and the better known species 

 indicates that future research will show that they share all the characteristics of the genus. 



(ZOOL. CHALL. EXP. — PART XLV. 1886.) Yy 9 



