TRACHELTPODA. 



85 



the animal advances in age, and provided with a sinus at 

 the lower part. 



Ge/iMs 23— STROMBUS Linnmis. 



Generic Character Shell ventrieose, base terminating 



in a short truncated, emarginated canal ; right lip dilating 

 with age into a simple, entire wing, lobed or crenulated 

 above, and provided with a sinus beneath, separated at the 

 base from the canal or notch ; aperture provided with a 

 long narrow horny operculum. 



Strombus Auris-DiancB Diana's Ear Strombus. Plate 



XL fig. 23. Oblong-ovate ; spire acute, tuberculated, and 

 transversely striated ; base recurved ; outer lip thick ; an- 

 terior lobe with a finger-like termination. Three inches 

 and a quarter long. Inhabits the Indian ocean. 



Genus 24 — PTEROCERA. —ZamarcA. 



Generic Character Shell oblong-ovate, ventrieose, ter- 

 minating in a lengthened canal ; outer lip dilating with age 

 into an expanded, rayed, or digitated wing, with a sinus 

 near the base ; spire short. 



Pterocera Chiragra — The Knotty Pterocera. Plate 

 XI. fig. 24. Ovate, tuberculated, with six digitated, canali- 

 culated rays, which are closed over in the adult shell; outer 

 lip internally striated. Six inches and a half long, exclusive 

 of the digitated lobes. Inhabits the Indian ocean. 



Genus 25 ROSTELLARIA Lamarck. 



Generic Character Shell fusiform or sub-t arreted, ter- 

 minated below by a beaked canal ; outer lip entire in some 

 species, and dentated in others, more or less dilated by age ; 

 with a sinus near the canal. 



Rostellaria Pes-pelecani The Pelican's Foot Ros- 



TELLARiA. Plate XL fig. 25. Turreted, flesh-coloured or 

 white ; body and volutions longitudinally ribbed, and crowned 

 with papillae ; base of body papillose ; outer lip palmate, 



H 



