76 Dr. T. Wright on Fossil Echinoderms 



surface, the greater elevation of the posterior than the anterior 

 half thereof, the inflated ridge-like eminence formed by the 

 single interambulacrum, and the well-defined character of the pori- 

 ferous avenues, form a group of characters by which E. Kleinii 

 is distinguished from its congeners. It has many points of 

 resemblance in common with E. ovalis ; but the greater length 

 of the ambulacral areas in this species makes a marked distinc- 

 tion between them ; moreover, in E. Kleinii the base is concave, 

 whilst in E. ovalis it is convex; the latter form is likewise 

 flatter and more oval, and its apical disc more excentral than in 

 E. Kleinii. 



Stratif/raphical position. Collected at Malta, from bed No. 2, 

 where it is very rare. It is found, according to Goldfuss, in the 

 Miocene beds at Biinde, Osnabruck, Astrapp, and Merminghiifen, 

 in Westphalia. 



History. Admirably figured and well described by Goldfuss. 

 The only Maltese specimen we have seen of this species is that 

 collected by the Earl Ducie, which is in his lordship's museum. 



Echinolampas Deshayesii, Desor, sp. PL IV. fig. 3 a-d. 



SYN. Echinolampas Hayesiana, Agassiz and Desor, Cat. raisonne, 

 Ann. Sc. Nat. torn. vii. p. 166. 



Test oval, depressed ; ambulacral areas narrow ; the poriferous 



zones contracted, without apparent connecting transverse sulci ; 



apical disc small and nearly central ; base convex ; mouth 



and anus large. 



Dimensions. Antero-posterior diameter 2 T 1 TT inches, trans- 

 verse diameter l T 9 n inch, height ^ths of an inch. 



Description. The form, size and structure of the ambulacral 

 areas afford the best guide to a knowledge of the numerous species 

 of this group. The Urchin before us has an oblong form, de- 

 pressed at the dorsal surface, convex at the base, and slightly 

 produced posteriorly. The ambulacral areas are narrow at their 

 widest part ; they are about one-sixth the width of the postero- 

 lateral interambulacra at the border. The poriferous zones are 

 narrow, and extend rather more than half-way down the dorsal 

 surface ; the pairs of pores are placed closely together, and the slit 

 or sulcus, which in general unites the inner and outer series 

 of pores together, is absent in this species, or at all events is not 

 apparent in the individuals before us ; the holes of both rows are 

 nearly of the same size. The interambulacral areas are wide ; 

 the antero-lateral are the narrowest ; the single interambulacrum 

 is slightly produced in the region of the anal opening. The 

 apical disc is small, and situated near the centre of the test, 



