MORPHOLOGICAL NOTES. 



37 



ling spines)) b}' STEERING in 1888, (1. c. p. XIV). They have usually 

 the form of a club or a mushroom, the head armed with short, strong, 

 retroverted teeth, their purpose being to hold the two pleopods to- 

 gether (fig. 66 69). The rami o the pleopoda are also very similar 



Fig. 68. Fig. 69. 



Oxyceplialus piscator. 



Fig. 70. Simorhynch- 

 otus Lilljeborgi. 



to those in the other Hyperids as well as in the Amphipoda Gammaridea. 

 The first large joint of the inner ramus carries a Deleft bristle)) (fig. 

 68 70), also first noticed by G. 0. SARS and minutely described by 

 Stebbing from many different forms of the ))Challenger)) Amphipoda. 

 The following joints are provided each with one pair of feathered 

 bristles. 



10. The urus and its appendages. 



The first segment of the urus is usually short, much shorter than 

 the last pleonal segment, except in Xiphocephalu s in which it is much 

 elongated, rod-like, and longer than the last pleonal segment. The 

 second and third segments are coalesced into one, and usually longer 

 than the first segment, the only exception being Xipho cephalus ar- 

 matus, in which the coalesced last ural segment is shorter than the first. 

 The last coalesced segment is comparatively broad in Simorhynchotus 

 (fig. 76), Tullbergella (fig. 74), Glossocephalus (fig. 71), and Steb- 

 bingella, more elongated in C ranocephalus (fig. 72), Oxycephalas 

 (fig. 75), Streetsia, Dorycephalus (fig. 73) Leptocotis, and Cala- 

 morhynchus, and lastly very narrow and rod-like in Xiphocephalus. 



The telson is invariably coalesced with the last ural segment in 

 all the genera of the Oxycephalidse, and this character not only 

 suggests the relation of the Oxycephaiidae with the Lycceidce, the Para- 



