174 



Contributions to Palceontology. 



AGLASPIS BARRANDI (n.s.), 

 PLATE VI. FIGS. 7-16. 



Carapace sublunate or semicircular, the diameter at base 

 being more than twice the length ; sides moderately 

 convex ; the middle more elevated, and showing indica- 

 tions of a trilobate character : front emarginate, or with 

 a distinct sinus ; the margin in front and sides limited 

 by an elevated and thickened border, which is slightly 

 extended at the posterior angles. Eyes large, broad-oval, 

 very prominent, situated near together, and anterior to 

 the centre of the carapace. Near the posterior margin 

 of the central division, there are two small pustules. 



Several fragments of thoracic articulations have been 

 obtained : these are all recurved, in greater or less degree, 

 at the extremities, without furrows upon the surface. A 

 single segment remains apparently entire: it is highly 

 arched, having an elevation nearly as great as the distance 

 of the extremities. This segment is probably from the 

 posterior part of the body. 



A single spine, three inches in length, and a fragment 

 of another similar one have been obtained. The texture 

 is everywhere minutely punctate, and the surface minutely 

 pustulose. 



Fig. 7, is the largest carapace obtained: one side is imperfect, and the 

 opposite angle broken off. The outline on the left is carried 

 out from other specimens, where that part is entire. 



Fig. 8, is a smaller carapace, not entire in front ; and the centre of the 

 anterior margin is covered by a bit of crust from some other 

 part, or some other individual. This specimen shows the 

 pustules on the posterior margin of the carapace. 



Fig. 9, is the inner side of a portion of a small carapace, showing the 

 cavities of the e} r es. 



Fig. 10. An enlargement of the surface, showing the texture. 

 Fig. 11. A segment of the body? probably from the posterior part of the 

 animal. 



Figs. 12, 13 & 14. Parts of segments ? showing the characters of the 

 extremities. 



