114 



PEDINOPSIS 



This genus was established by M. Cotteau in his memoiri on ' Les Echinides 

 des Pyrenees/ and placed near Pseudodiadema, with which it has many affinities ; the 

 tubercles are crenulated and perforated, and the pores bigeminal throughout, a character 

 which is in part possessed by Ps. Brongniarti, variolare, &c. It has affinities with 

 Salmacis in the number of its pores ; in this genus, however, they are arranged in triple 

 oblique pairs, whilst in Pedinopsis they are regularly bigeminal throughout. 



The original specimen was collected from the Neocomian strata of Aude, where it is 

 rare ; another of the same species has been found at Caussols (Var) ; the one which I 

 now figure was obtained from the Chloritic Marl near Chardstock, Somerset. 



Pedinopsis Wiesti, Wright, nov. sp. PI. XIV, fig. 1 ; PI. XXIX a. 



Test moderate in size, circular, inflated at the sides, convex on the upper surface, and 

 flat at the base ; ambulacra with two complete marginal rows and two inner incomplete 

 rows of tubercles ; inter-ambulacra with six rows of turbercles at the ambitus, the two 

 central of which are complete, and the four lateral incomplete ; tubercles nearly all of the 

 same size ; pores uniformly bigeminal throughout. 



Biviensions. — Height one inch ; transverse diameter one inch and seven tenths ; 

 mouth-opening six tenths of an inch. 



Description. — This rare Urchin forms the type of a new genus, established by my friend 

 M. Cotteau for a similar rare species from the Neocomian of Caussols (Var). The test is 

 of moderate size, circular at the ambitus, inflated at the sides, convex on the upper 

 surface, and flattened at the base. The arabulacral areas are moderately wide, and retain 

 their proportional diameter throughout the area ; they have two rows of marginal 

 tubercles of small size, which extend from the peristome to the disc (PI. XXIX a, fig. 1), 

 and are very regular both in size and arrangement ; between the base and upper surface two 

 other rows occupy the centre, so that this area at the ambitus is furnished with four rows 

 of tubercles (PL XXIX a, fig. 1 g), the two inner rows of which disappear at the lower 

 seventh (fig. I h) and upper third of the areas (fig. 1 d) ; the tubercles are nearly all of the 

 same size ; around the base of the bosses some fine granules are sparsely distributed, 

 which form impeifect circlets around them (PI. XXIX a, figs. 1 d, e,f,g, h). None of 

 the marginal rows in the specimen is complete, so that the exact number in each series 

 cannot be ascertained ; but as thirty can be counted in one incomplete column, six more 

 may be fairly estimated as wanting (fig. 1 a, b, c). 



The poriferous zones are moderately wide, and very uniform in diameter throughout, 



1 "Echiiiides foss. des Pyrenees," p, 16. E.xtrait du ' Congres scientifique de France,' 28" session, 

 tenue a Bordeaux, t. iii, pi. ix, 18(53. 



