6 



BRITISH FOSSILS. 



6. Diadenia homostigma, Ag. (sec. Desor), Ech. Suiss. ii. p. 24, t. 17, f. 1-5. 

 Zom/i^.— CoRNBRASH, Stanton, &c., Wilts (W. Buy). 



7. D. vaganSf Phil, sp., Geol. Yorks., t. 7. f. 1. 



Locality. — Cornbrash, Yorkshire. (Morris's Cat. p. 77). 



[The Cidaris Bechei, Brod. in Geol. Proc. vol.ii. p. 202 (not Geol. Tr. 2. ser. 2. t. 4. 

 f. 5.), from the Lias of Lyme Kegis, was considered a Diadema by Prof. Porbes. 

 The original specimen is in the Mus. Geol. Soc. Prom the condition of the 

 specimen it would be quite indeterminable, but comparison with better examples 

 developed by Dr. Wright shows it to be an Echinopsis.'] 



8. i>. Bakeries, Woodw. 



Body sub-pentagonal, depressed ; lat. 16, alt. 7 lines ; diameter of buccal opening 7 lines, 

 anal 4 lines ; primary tubercles prominent, in 2 rows of about 13 each, on all the areas ; 

 bosses crenulated ; interspaces sparingly granulated, becoming bare above ; pores in 

 single file. 



Locality. — Coenbrash, Caistor, Northamptonshire. Collected by Miss Baker. (Coll. 

 Brit. Mus.) 



[The Diadema minimum, Ag., of Morris's Catalogue {Diadema minuta, Buckman), 

 is an Acrosalenia, and was first described by Quenstedt under the name of Cidarites 

 criniferus.'] 



9. D. iiubangulare," Ag., Ech. Suisses, iv. 19. t. 17. f. 21, 22. (not of Goldiuss). 

 Cidaris versipora. Woodw. MS. Morris's Cat. 1st edit. p. 50. Bronn, Index, p. 301. 



Localities. — Coral Rag, Calne and Hillmarton, Wilts ; Parringdon, Berks. 



There are two varieties of this species ; one with the upper surface evenly inclined 

 all round, the other tumid at the angles and depressed in the centre above. The 

 spines are like those of D, pseudodiadema. The figure given by Agassiz agrees with 

 a Swiss specimen in the Brit. Mus., and differs from the British examples in having 

 fewer and more prominent primary tubercles, especially on the ambulacral areas, 

 (viz. 11 instead of 13 to 16 in each row), and the ambulacral rows are not so 

 widely separated by a finely granulated space. 



We cannot agree with M. Agassiz in considering either of these forms referable to 

 the '''■Cidarites suhangularis " of Goldfuss (Petr. 1. 122. t. 40. f. 8.) German 

 specimens, agreeing with Goldfuss's figure and description in the presence of only 

 a single series of pores, are in the British Museum. 



Section B. (Diplopodia, M'Coy), Pores crowded above and below. 



10. D. psntagonum (Diplopodia), M'Coy, 1848, Ann. Nat. Hist. p. 412. 



Locality. — Great Oolite, Minchinhampton. (Woodw. Mus., Brit. Mus., &c.) 



In this little species the pores are crowded at the ends of the ambulacra, as in D. *' sub- 

 angulare ; " the character has not been considered of generic importance by 

 M. Agassiz or Prof. Porbes, either here or in the cretaceous and recent species, 

 but it has been adopted ])y M. Desor. 



* * Cretaceous Species. 

 Section A. Primary tubercles in two rows ; pores in single file. (Pseudodiadema.) 



11. D. ornatum, Cidarites, Goldfuss, Petr. t. 40. f. 10. (Porbes, in Mus, Pract. Geol. and 

 Morris's Cat. 2nd edit.) Cyphosoma Milleri, part, Porbes, in Dixon, Geol. Sussex, pp. x. 

 and 340, pi. 25, f. 17. (Mus. Bowerbank.) 



In the first edition of Morris's Catalogue this name was introduced, at my suggestion, 

 for the Warminster fossil, afterwards considered distinct and named D. Beneltift. 



