56 MOLLUSCA FROM THE CRAG. 



had seven convex volutions, covered with obtuse nodules, about a dozen in each 

 volution, with half a dozen elevated transverse lines. At the upper part, near the 

 suture, there is a row of small denticulations. The first two volutions are smooth, 

 with a very obtuse apex, in which character it disagrees with the French fossil, 

 where it is sharp and pointed. 



Clavatula,* Lam. 1801. 



Mangelia. Leach. Risso. 1826. 

 Defrancia. Miller. 1826. 

 Mangilia. Loven. 1846. 



Gen. Char. Shell fusiform, turreted, rarely of any great size, generally ribbed 

 in a longitudinal direction, and transversely striated ; aperture ovate, terminating 

 in a somewhat short, open, canal; outer lip sharp, sometimes denticulated within, 

 with a small sinus at the suture. 



This name was proposed by Lamarck for a division of the Pleurotoma3, to contain 

 those species with a small and shallow sinus, which he afterwards, in his ' Hist, des 

 An. sans Vert.,' united to Pleurotoma. The shells here intended to be grouped 

 together are those in which the " side slit " is represented by a somewhat obscure 

 sinus, and that, instead of being in the outer lip, is situated at the upper extremity 

 of the aperture, at or near the junction of the body whorl. The name Mangelia 

 was given in MS. by Dr. Leach to some shells of this character in the British 

 Museum ; and this name was adopted by Risso, in his ' Hist, of the Shells of Merid. 

 Europe.' Messrs. Reeve and Sowerby have recently employed it for the same 

 shells ; Lamarck's name is, however, of prior date. 



Many recent species of this genus are found within the tropics, others have been 

 obtained in the Arctic seas. 



1. Clavatula linbaeis. Mont. Tab. VII, fig. 2, 2 a. 



Murex linearis. Mont. Test. Brit. p. 261, t. 9, fig. 4, 1803. 



— elegans. Bon. Brit. Shells, t. 1 79, fig. 3. 

 Fusus linearis. Flern. Brit. An. p. 350. 1828. 

 Pleurotoma linearis. Thorpe. Brit. Mar. An. p. 197, 1844. 



— S. Wood. Catalogue 1842. 



Mangelia linearis. Leach. 

 Defrancia linearis. Lovin. Ind. Moll. Scand. p. 13, 1846. 



CI. Testa turriculd, fusiformi, subventricosd, spird elevatd, acuminata ; anfractibus 

 converts, longitudinalitcr costatis ; transversim lineatis, lineis elevatis, striatis, labro 

 incrassato, intus Icevi ; canali brevi. 



Shell fusiform and turriculate, with an elevated and acute spire; whorls convex, 

 longitudinally costated, and sharply striated transversely; lip thickened on the 

 outside, smooth within ; canal short, rather broad. 



* Etym. (?) Clavatula, the diminutive of clava, a club. 



