THE FAMILY OXYCEPHALID^E. 45 



He distinguished the two genera Oxycephalus and Rhabdosoma 

 from one another by the length of the rostrum and of the uropods. 



In 1862 SPENCE BATE (20, p. 341) made the subfamily a family 

 of its own, and in 1885 CARUS (33, p. 427) considered it as a subfamily 

 of the family Platyscelidce. 



The family OXYCEPHALIDJE, SPENCE BATE, 1861. 



Diagn. The head is more or less elongated and rostrate. 



The eyes are large, but do not occupy the whole head. 



The first pair of antennae are curved (<i), and fixed on the 

 under side of the head; the first joint of the flagellum is 

 very large, and tumid; the following, joints are small, few 

 in number, and subterminal (c?). The second pair are fixed 

 on the under side of the head, are long, slender, and folded 

 four times (cf), or are entirely wanting (5). 



The mouth-organs are reduced, the maxillse being rudimentary; 

 the mandibles are provided with an elongated palp (tf), or 

 without a palp (<?). 



The last five pairs of perceopoda are walking legs; the femur 

 of the last three pairs is not transformed. The seventh pair 

 are complete. The ovitectrices are well developed. 



The uropoda are provided with rami. 



The telson is coalesced with the last ural segment. 



In 1887, in my preliminary ^Systematical list I enumerated five 

 genera, in addition to Rhabdosoma or Xiphocephalus, as composing the 

 family Oxycephalidae, viz: Glossocephalus, Oxycephalus, Lepto- 

 cotis, Tullbergella, and Calamorhynchus; a sixth genus Streetsia, 

 was proposed in 1888 by STEBBING; and here I increase the number of 

 genera to ten by transferring the genus Simorhynchotus from the 

 Lycceidce to this family, and by introducing three new genera, viz: Cra- 

 nocephalus, Stebbingella, and Dorycephalus. 



Of these genera Simorhynchotus shows some relation to 

 Lycceidce, Tullbergella to Euthamneidce, Cranocephalus and Steb- 

 bingella to Eutyphidce, Glossocephalus to Phorcoraphidce, and Dory- 

 cephalus and Leptocotis to Xiphocephalidce. 



These ten genera may be distinguished by the characteristics 

 shown in the following synoptical table: 



