130 DICHELASPIS ORTHOGONIA. 



rami of the second cirrus ; thickly clothed with bristles : 

 rami of the second cirrus of equal thickness, but little 

 shorter than those of the sixth cirrus ; the three or four 

 basal segments of the anterior ramus are thickly clothed 

 with spines ; the other segments, and all the segments 

 on the third pair, resemble the segments of the three 

 posterior pair. These latter are elongated, not pro- 

 tuberant, and support eight pairs of spines with very 

 minute intermediate spines ; those in the dorsal tufts are 

 numerous and long. 



Caudal Appendages nearly as long as the pedicels of the 

 sixth cirrus ; oval, moderately pointed, with their sides, 

 for one fourth of their length, thickly clothed with long 

 very thin spines. 



Affinities. — In the form of the scuta and of the carina 

 this species is most nearly allied to D. Grayii or D. pel- 

 htcida, in the form of the terga to D. WarwicTcii. 



5. DlCHELASPIS ORTHOGONIA. PI. II, fig. 10. 



D. scutorum basali segmento angustiore quam occludens 

 segmentum ; longitudine fere dimidid ; duorwm segmentorum 

 junctione calcared : tergorum prominentiis marginalibus 

 incequalibus quinque : carina deorsimi in parvo calyce 

 lunato terminatd. 



Scuta with the basal segment narrower than the 

 occludent segment, and about half as long as it ; junction 

 of the two segments calcified. Terga with five unequal 

 marginal projections. Carina terminating downwards in 

 a small crescent- formed cup. 



Maxillae with the inferior part of edge much upraised. 



Hab. unknown ; associated with Scalpellum rutilum, apparently attached 

 to a horny coralline. British Museum. 



The specimens are in a bad condition, not one with 

 all the valves in their proper positions, and most of them 

 broken ; animal's body much decayed and fragile. 



