4. 



BRITISH FOSSILS. 



straight and simple, pairs of pores very oblique ; tubercles minute, pro- 

 minent, imperforated, and crenulated ; areola? small, radiated, with 

 elongated miliary granules, sutures grooved ; interambulacra with two 

 rows of 7, 8 tubercles; ambulacra very narrow, with 7 or 8 tubercles, 

 alternate and irregular. 



Locality. — Lower Chalk, Dover (Mus. Brit, and Bowerbank). This 

 small but very distinct species has only been found in the hard 

 White Chalk, along with C. simplex and Salenia granulosa. 



10. C. 3Iiddletoni, n. sp. 



Body circular, tumid, concave beneath ; lat. 10, alt. 6 lines ; mouth 

 small, depressed, lat. 3^ lines ; apical opening pentagonal, elongated, 

 lat. 4-5^ lines ; pores in single file ; primary tubercles small, in sub-equal 

 rows of 12 each, the 6 uppermost minute ; areolte large at the circum- 

 ference, nearly confluent ; interambulacral tubercles bordered above by 

 6 nearly equal accessories, and divided by a broad furrow, smooth in the 

 centre : secondary tubercles also developed on the base. 



Locality. — Upper Chalk, Norwich^ This unique specimen was 

 placed in the hands of Prof. Forbes, for description, by John Mid- 

 dle ton, Esq., of Norwich. 



Salenl^, Gray. 



In the 2nd edition of Prof. Morris's Catalogue of British Fossils, p. S9, 

 the following species of Salenia are referred to, as described by Prof. 

 Forbes in Decade Y. No MS. having been left, the following notes are 

 drawn up from the type specimens in the Museum of Practical Geology. 



1. Salenia Austeni, Lower Chalk, Dover. 



2. S. Bunburyi, Lower Chalk, Mildenhall. 



3. *S'. Clarkii, Lower Chalk, Dover. 



4. S. clathrata (Ag. MvS.), Upper Green Sand, Warminsier. 



5. *S'. granulosa, Lower Chalk, Dover. 



6. S. Portlockii, Upper Chalk, Ireland. 



7. S. umbrella (Ag. MS.), Upper Green Sand, Warminster. 



8. S. ornata (Ag. MS.), Upper Green Sand, Warminster (Decade I. 



5, p. 2). 



1. /S. Forbes, MS. JJike S. petalifera,'DQsm, 



Body tumid, depressed, lat. 10, alt. 6 lines ; apical disk comparatively 

 small, 5 lines in diameter ; the plates ornamented with serrated ridges 

 running in pairs from their centres, and meeting to form a sort of trellis. 

 Two of the original specimens, in the Museum of Practical Geology, 

 are more distinct from ^S*. petalifera than any other examples. The 

 apical disk of S. petalifera is very finely granulated, but, as 

 remarked by Prof. Forbes (Decade I. 5, p. 3), "a few rare 

 specimens exhibit indistinct indications of radiated ribbing." In 

 the Grey Chalk of Dover, some examples are nearly plain, others 



