68 TRACHELIPODA. 



fig. 11. Shell cylindrical, white, with one plait on the col- 

 lunella. Half an inch long. Inhabits the British seas. 



Genus 8.— MARGINELLA.— Zamarc^. 



Generic Character. — Shell oblong-ovate, smooth; spire short, 

 (uter lip with a marginal longitudinal varix j base slightly 

 notched ; columella plaited ; folds nearly equal. 



The thickening of the outer lip characterises these shells from the genus 

 Volvaria and Mitra. 



Section I. — Spire prominent. 



Marcjinella carulescens.—TaE Bluish Marginella. Plate 

 XI. fig 6. Shell bluish-white ; spire short, and acute ; lip 

 brownish purple within ; columella with four plaits. One inch 

 long. Inhabits the Indian ocean. 



Section IL — Spire not prominent. 



Genus 9. — VOLUTA Linnaus. 



Generic Character. — Shell ovate, more or less ventricose ; 

 apex papillose ; without a canal; columella plicate, the lower 

 plaits larger and more oblique than the others ; without colu- 

 mellar laminae. 



This genus is divided into four sections. — 1. Shell ventri- 

 cose ; 2. shell ovate, spinous, or tubercular ; 3. shell oval, and 



subtubercular ; 4'. shell elongated, ventricose, nearly fusiform 



The following illustrates section 2. 



Valuta vespertilla. — The Bat Volute. Plate XI. fig. 7. 

 Shell emarginated with acute spines on the volutions ; summit 

 slightly obtuse , columella four plaited. Three inches long. 

 Inhabits the Indian seas. 



Genus \0.—MlTB.K.— Lamarck. 



Generic Character. — Shell turrited, or sub-fusiform, with 

 an acute spire ; base emarginate, without a canal ; columella, 

 plicated; the plaits being parallel and transverse, the lower ones 

 smallest ; pillar lip thin and adnate. 



Mitra pontificalis. — The Pontifical Mitra. Plate XI. fig. 



