56 THE VOYAGE OF H.M.S. CHALLENGER. 



to Ije seen at the frout margin of the segmeut between the origiu of the two mandibles. 

 The three following thoracic segments are short ; the two middle segments are 

 furnished like the cephalothoracic segments dorsally at their hinder margin with an 

 elevated prickle. The lateral processes which serve for the insertion of the legs, are of 

 considerable length; at their extremities they bear a strong prickle, which is not quite 

 so Ions; as those on the middle of the dorsal surface. 



The mandibles consist of a single joint, bearing at its extremity a rudimentary 

 triangular second joint. 



The palpi are slender and comparatively long ; the first two joints are extremely 

 small, the third joint is the longest ; the relative length of the other joints is nearly the 

 same as in the palpi of Ascorhynchvs glaher. The distal extremity of the fifth joint and 

 the whole surface of the four following joints show on the one side numerous haii-s 

 of the curious form observed and descriljcd by Bohm for Ascorhynchus ramipes, 

 Bohm (sp.) {Gnamiitorliynchvs rami2'>€S, Bohm) (PI. VI. fig. IG). 



The ovigerous legs are comparatively short, 5 mm. in the specimens of 6 '4 mm. The 

 first joint is very small, the two following are a little longer, the fourth and fifth are 

 very long, the sixth a great deal shorter; the four last joints (PL VI. fig. 12) are very 

 short, and about the same length, the claw is not so extremely short as in Ascorhynchus 

 glaher. The denticulated spines are placed in three distinct rows (PI. VI. fig. 13). 



The first joints of the legs are furnished dorsally with strong prickles, like those of the 

 dorsal surface of the l)ody and the lateral processes. The first joint of the leg is furnished 

 with two, the second joint, which is Ijut little longer than the first, with a single prickle. 

 On the third joint, which is nearly as long as the first, no prickles are to be seen. The 

 fourth is shorter than the fifth ; the latter, the longest of all, is also a little longer than 

 the sixth joint. Of the two last joints the first is a little shorter than the second (PL 

 VI. fig. 14). The claw is longer than half the length of the second tarsal joint. 

 Accessory claws arc wanting. The first pair of legs, which is much feebler than the 

 three following paii's, has a very small claw (PL VI. fig. 15). 



Both specimens of this species collected during the cruise of H.M.S. Challenger are 

 males. I observed small genital pores on the two hinder legs at the place which, as 

 fiir as my knowledge goes, they invariably occupy. One of these males bears larvae, 

 for the description of which see below. 



Habitat. — The specimens of Ascorhynchvs mhmtus were dredged in the neighbourhood 

 of Melbourne, at 



Station 161. April 1, 1874. Ofi' entrance to Port Philip. Depth, 38 flxthoms. Sea 

 bottom, sand. 



Observations. — This species seems to l)e nearly allied to Ascorhynchus 7'amipes, Bohm 

 (sp.). Yet it may be easily distinguished from it ])y the follomng characteristics: — 



1. The total length of the Ijody of Ascorhynchus ramipes is 11 mm., of the proboscis 



