BRITISH FOSSILS. 



Decade L Plate X. 



NUOLEOLITES (CATOPYGUS) CARINATUS. 



[Genus NUCLEOLITES. Lammick. (Sub-kingdom Radiata. Class Echinodermata. 

 Order Echinidse. Family Clypeasteridse.) Body orbicular, oval, or cordate, more or less 

 tumid, sometimes much depressed 5 ambulacra dorsally petaloid ; anus supra-marginal ; 

 mouth sub-central.] 



[Sub-genus Catopygus. Outline narrowing anteriorly ; body truncated posteriorly, with 

 the anus on the superior surface of the truncation. Tubercles around mouth conspicuous.] 



Synonyms. Nucleolites carinatus^ Goldfuss, Pet. Germ., p. 142, pi. 

 43, f. 4, a~c. Catopygus carinatus, Agassiz, Cat. Syst., p. 4. Agassiz 

 and Desor, Cat. Pais, des Echin,, Ann. Sc. Nat., 3rd ser., vol. vii., p. 157. 

 Bronn, Lethaea Geog., p. 613 ; Index Paleont., p. 249. Morris, Cat., 

 p. 49. 



Diagnosis. N. ( Catopygus) ambitu ovali sen suhrotundo, postice plus 

 minusve dilatato ; dorse convexo^ prope anum obsolete carinato ; apice excen- 

 trico, vertice post apicem ; ambulacris lineari-lanceolatis ; extremitate anali 

 truncata supra anum prominente^ subapiculata, ano suboblongo in parte 

 superiori posito ; ventre convexiusculo, 



Var. a. ovato-rotunda, dorso tumido. — Nucleolites carinatus, Goldfuss, 

 Pet. Germ., pi. 43, f. 4, a-c. 



Var. /3. ovata, dorso antice decliveiite. — Nucleolites columbarius, D'Ar- 

 CHiAc, Mem. Geol. Soc. France, 2nd ser., vol. ii., pi. 13, fig. 3, a^b^c'^ 



Var. y. oblonga. 



Var. ^. subglobosa. 



The clear and distinct history of this fossil urchin dates from the 

 excellent figure and description given by Goldfuss in the Petrefacta 

 Germanica, where the Nucleolites columbaria of Lamarck is cited as a 

 questionable synonym, and the Echinites pyriformis of Parkinson re- 

 ferred to without mark of doubt. Parkinson's species (Organic Remains, 

 V. iii. pi. 3, f. 6), however, was from the Maestricht beds, and was rightly 

 identified by him with the Echinites pyriformis of Leske (t. 44, f. 7 and 

 51, f. 5, 6), which circumstance seems to have escaped Goldfuss, who 

 quotes the figures in Leske for his Nucleolites pyriformis (Pet. Germ., 

 p. 141, t. 43^ f. 7, a—f) A comparison of specimens of the Maes- 

 tricht fossils with ours has confirmed their distinctness ; the anus in the 



[l. X.] L 



