63 



and Z. rugosus, but differs sufficiently from both to warrant a name. The 

 Jumpers ; Div. 4, A. G. J. Richardson. 



The above description, it will be understood, as it is founded on a single 

 individual, may require alteration when further material shall have been 

 procured. 



Genus Sphaerocoryphe, Angelin. 



S. Salteri, n. sp. — GlaboUa sub-globular, so much inflated that its 

 convex sides overhang the base all round ; neck furrow rather large with 

 a tubercle in it on each side, within and close to the dorsal furrow ; neck 

 segment with its margin abruptly elevated, the surface sloping forwards 

 into the furrow ; a deep concave groove runs outwards close to the posterior 

 margin to the angles of the head, which appears to be produced into 

 short spines. The width of the neck segment is about one-fourth less than 

 the greatest width of the glabella. The dorsal furrows are deep and con- 

 cave. The front part of the glabella is, in all the specimens that have 

 been examined imbedded in the matrix, and it cannot therefore be 

 determined whether or not it overhangs the margin. From the small 

 tubercle in the neck furrow on each side, a low rounded ridge runs out- 

 wards across the neck furrow. 



Length of the head 2i lines ; length of the glabella two lines ; width of 

 the neck furrow half a line. These are the dimensions of the largest 

 specimen. Another very small specimen gives the following. Length of 

 the head li lines; length of glabella one line ; length of the posterior 

 margin of the head from the dorsal furrow to the outer angle one line ; 

 length of the spine half a line. The width of the head is therefore about 

 twice its. length. . 



This species is undoubtedly congeneric with Stauroeephalus iinieus, 

 Thompson, as figured by Salter*. It differs in having the glabella more 

 uniformly globular, and in the characters of the neck. In S. unicus, close 

 under the base of the glabella behind, there is a rounded groove across the 

 neck ; then a rounded ridge with a tubercle at each end on the sides of 

 the neck ; behind this is the true neck furrow. In this species the 

 tubercles are not connected by a ridge, but on their outsides a ridge runs 

 to the cheeks. 



It is more closely allied to S. granulata^ Angelin, differing therefrom 

 only, so far as can be made out from the figures, in being much more 

 finely tubercled on the surface, and in the neck furrows more deeply 

 excavated. 



Only three specimens were found, two of which are above noticed, but 

 the third shows nothing but the upper part of the convex glabella. The 



° Salter, " British Trilolites," pi. VII, figs. 22, 24. 



