Mr. R. Tate on a new Genus o/" Cerithiadte. 417 



Otiorhynckm stdcatiis, Schonh., Gen. et Spec. Cure. ii. 620 (1834). 

 ^ Stierl., Rev. der Otiorh. 225 (1861). 



A single example of the common European 0. sulcatus, 

 which seems to me to differ in no respect from the ordinary 

 type, is amongst the Coleoptera which were collected at St. 

 Helena by Mr. Melliss ; hut, if truly established in the island, 

 as the species appears to have become at the Azores, there can 

 be little doubt that it has been naturalized accidentally from 

 more northern latitudes. 



[To be continued.] 



L. — Contributions to Jurassic Palaeontology. 

 By Ralph Tate, Assoc. Linn. Soc, F.G.S., &c. 



1. Cryptaulax, a new Qenus o/ Cerithiadse. 



CeritMum^ in the numerical strength of its recent and fossil 

 species, ranks among the largest of the generic groups of 

 Gasteropods. The number in the Jurassic rocks referred to 

 the genus is very great, their alliance is not in all cases 

 certain, and any steps that tend to reduce the number of 

 species will be fraught with convenience to the working 

 paleontologist. 



Of late a few genera have been constituted out of species 

 previously referred to Cerithium : Piette (1861) established 

 the genus Exelissa for the reception of the somewhat pupjeform 

 Cerithia with an entire aperture and the last whorl cylindrical 

 and contracted at the base. The typical species is C. strangu- 

 latum^ D' Archiac ; and fourteen species, ranging from the 

 Middle Lias to the Kimmeridge Clay, should be referred to 

 the genus. Lycett, in the ' Supplement to the Mollusca of the 

 Great Oolite,' p. 93 (1863), applied to the same group the 

 generic title of Kilvertia, referring to it the type species pre- 

 viously used by Piette : Kilvertia is therefore a synonym of 

 Exelissa. 



The British species are : — E. constricta^ E. pulchra, E. for- 

 mosa^ and E. siJicula, Lycett, sp., from the Great Oolite; E. 

 strangulata^ D' Archiac, sp., from the Great Oolite and In- 

 ferior Oolite ; and E. numismalis, n. sp., from the Middle Lias. 



Exelissa numtsmalis, n. sp. 



Shell small, cylindrical, turreted, acute ; whorls subrotund, • 

 longitudinally ribbed ; ribs three in number, large, and coarsely 

 nodulated, interstitial spaces very narrow ; the last whorl 

 slightly contracted at the base, the two lower ribs of the upper 

 half often without nodules, and with a small flat rib between ; 



Ann. (& Mag. N. Hist. Ser.4. Vol.iv. 30 



