DYSPONTIUS. 67 



of the outer branches small, lancet-shaped, and 

 bordered with extremely minute cilia; the first joint of 

 the inner branch has a spine and a long seta near the 

 middle of its inner edge, the second a spine and three 

 setae, as well as four apical spines, two of which are 

 minute ; the third joint also has two spines on its outer 

 margin. The peduncle of each swimming-foot is pro- 

 duced internallyinto a very large and prominent rounded 

 angle (figs. 8, 9, a, a). Fourth pair of feet (fig. 9) elon- 

 gated, 1-branched, destitute of marginal spines; firstand 

 second joints with one seta, third with four seta3 and a 

 long terminal spine. No fifth foot. First abdominal 

 segment bearing at the posterior angles three slender 

 spine-like setae (fig. 10). Abdominal somites, except 

 the first, much broader than long ; caudal segments 

 scarcely longer than broad, about equal to the last ring 

 of the abdomen ; seta? five, the longest about equal in 

 length to the abdomen, the next half as long, the rest 

 very small. The shell is semi4ransparent, rather thick, 

 corrugated (fig. 13), and mare- or less sparingly beset 

 with minute prickles on some portions of the cuticular 

 surface. Length -^th of an inch (1*8 mm.}. 



This, though widely distributed, seems to be a very 

 scarce species ; in most of the localities here noted it 

 was represented only by a single example. On weeds 

 at Tobermory and Hillswick (Shetland), (Rev. A. M. 

 Norman) ; dredged in a depth of forty fathoms off 

 St. Agnes, Scilly Islands ; in twenty-seven fathoms off 

 Hawthorn (Durham) ; in thirty-five fathoms off Red 

 Cliff and Robin Hood's Bay (Yorkshire). 



The number and proportions of the antennal joints 



