DORYCKPHALUS. 75 



Gen. 5. Dorycephalus, n. g. 



Derivatio: Söqv = a spear, and xttfiaXoç = a large-headed fish, see Aristoteles. 



Diagn. The head is long and narrow, produced into a comparatively 



short, narrow, sharp-pointed rostrum, which is closed on the 



under side. The hind part of the head is constricted, forming 



a short, cylindrical neck. 

 The second pair of antennœ are hidden under the head, when 



folded. 

 The first two jjairs of perœopoda are subcheliform, or the 



second are cheliform. The carpus and metacarpus of the 



fifth pair are not dilated. 

 The last coalesced ural segment is a little more than twice 



as long as the first, and somewhat more than three times 



as long as broad. 

 The inner ramus of the third pair of uropoda is coalesced 



with the corresponding peduncle. 

 The telson is narrowly triangular. 



This new genus closelj' resembles Leptocotis in general form of 

 body, but differs in the comparatively shorter and broader last ural 

 segment and uropoda, and by the inner ramus of the last pair of uropoda 

 being coalesced with the peduncle. The type for the genus is Leptocotis 

 Lindstroemi, briefly described by me in 1887 (35, p. 38). The new 

 species Leptocotis ambobus^ proposed by Stebbing in 1888 (39, p. 1594) 

 certainly belongs to this genus, and at my first comparison of Stebbing's 

 species with my own I supposed them to be identical, but after a close 

 re-examination of my specimens I must allow that there are some small 

 differences, which can scarcely be explained as individual variations; but 

 on the other hand both are easily distinguished from Leptocotis tenuiro.stris, 

 Glaus, and L. spinigera^ Streets, by the form of the urus and its 

 appendages. Such being the case I record them here as two distinct 

 species. 



A. The second pair of perœopoda are subcheliform. The 



femur of the seventh pair is half as long as that of 



the sixth. 1. D. Lindstroemi. 



B. The second pair of peraeopoda are cheliform. The femur 



of the seventh pair is not half as long as that of 



the sixth. 2. D. anibobus. 



