LSG CERITHIADiE. 



bus, and Pteroceras, wliicli belong to a distinct family. 

 The affinities of AporrJiais with CerWiium have been 

 observed by Swainson and others, and are very evident 

 when we look at the yonng shells of the former, or com- 

 pare the animals of both. There are not a few fossil 

 species of this genus, ranging far back in time. 



A. PEs-cARBONis, Brongniart. 



Spire shorter than body ; digitations usually five, narrow and 

 produced ; the caudal one very long and narrow, its point either 

 straight or inclined upwards. 



Plate LXXXIX. fig. 5, 6. 



pes carhonis, Brong. Terr, du Vicont. p. 75, pi. 4, f. 2. 

 Jiostallaria Serresiana, Michaud, Bull. Linn. Soc. Bordeaux, vol. ii. pi. 1, f. 3, 4 

 (fossil) ; copied, Ferus. Bull. Scienc. Natur. 

 vol. xvii. p. 308. — Potiez and Mich. Galerie 

 Douai, Moll. vol. i. p. 449. 

 „ pes-peJecani, var. Kiener, Coq. Vivant. Rost. pi. 4, f. 1, c. 



Aporrhais pes-carbo7iis, Sowerbv, Thesaur. Conch, vol. i. p. 21, pi. 5, f. 1. 

 CJienopus „ Desh. Lam. Anim. s. Vert. (ed. Desh.) vol. ix. p. 657. 



„ Serresianus, Philippi, Moll. Sicil. vol. ii. p. 185, pi. 27, f. 6. 



We owe to the researches of that enterprizing naturalist 

 R. M'Andrew of Liverpool, among the less accessible por- 

 tions of the British Islands, the addition of one of the very 

 few recent species of this genus, to the Fauna of Great 

 Britain. 



Exclusive of the extremely dilated outer lip the shape is 

 fusiform, and greatly attenuated at both extremities. The 

 shell, although moderately strong, is less so than are the 

 other two known recent species of Jporrhais, is more or 

 less opaque, not much polished, and of an uniform paler or 

 darker tawny hue ; the ivory-like enamel which lines the outer 

 lip, and is spread over a considerable portion of the ventral 



