336 Mr. H. Seeley on two new species of Chalk Starfishes. 



surface, bearing the hill-like prominences, rises. The superior 

 oculars are greatly developed, and more swollen than the inter- 

 mediate bones ; they are one and a half times as large as the 

 latter, and, in size and shape, look as though formed of an 

 ordinary marginal and the half of another divided diagonally ; 

 they carry three rows of prominences, and have a rabbet on the 

 inner edge similar to that on the others. The superior plates are 

 steep and deep, compared with the inferior plates, over which they 

 slightly project, so that when the under surface is seen, the margin 

 appears step-like. The under-plates on a side were in all six in 

 number, one being under each intermediate marginal, and two 

 under each of the eye-plates ; they are flat, smooth, and rounded- 

 off at their outer edge. The margin of each inferior ossicle is bor- 

 dered by a slight rabbet, the walls of which are connected by a 

 number of partitions which give it the look of a line of little pits. 

 The fragment consists of one complete side, wanting only a ter- 

 minal inferior ocular plate. It measures in length ^ths of an inch. 



This species is easily distinguished from every other by the 

 number of its superior marginals. In size it comes nearest to 

 rugatus, Forbes, which it is not unlike in the markings on its 

 dorsal marginal ossicles, 



Chalk of Hertford. 



Goniaster (Goniodiscus) Furnivalli, S. 



Body pentagonal, with sides gently curved outwards. When 

 perfect, having on the dorsal sur- 

 face, in each side, ten oblong, con- 

 vex, rather finely-granulated mar- 

 ginal ossicles, all steep or abrupt, 

 and deep. Of these the oculars 

 are not preserved, but must have 

 been small and triangular, and 

 have projected slightly over the 

 inferiors. Of the four interme- 

 diate marginals the two middle 

 ones are slightly the shorter ; this 

 arises from the inner side of the 

 outer intermediate marginals 

 sloping towards the outer side, and 

 so, with the ossicles between, form- 

 ing a gentle curve ; but all four 

 are of the same width, and rather 

 wider than the others. The inferior 

 ossicles are eight, flat, finely punc- 

 tate, all of nearly the same width 

 (the two middle being slightly Upper surface. 



Under surface. 



