Mr. G. B. Smverby on the recent species of Ovulum. 145 



Art. XVI. On the recent species of the Genus OVULUM,^ 

 By G. B. SowERsy, F.L.S.^ 4*c. 



OVULUM. 

 OvULA. Lamarck, Hist. Nat. des Anim. sans vert. VII. p. 366. 

 Sowerby, Genera of Shells, No. II. 

 OvuLus, Radius, Calpurnus, Ultimus, Montf. 

 OvuLA, SiMNiA, Leach. 

 Testa ovata vet ovato-oblonga, plerumque ventricosa, spird occultd. 

 Apertura longitudinalis, elongata, suprd artgusta^ infrd latior; extre- 

 milatihus emarginatis et in canales plus minusve productis; lahio 

 interna edentulo; externa rarissime tenui, acuta, plerumque incras- 

 satOy involuto, interdum IcBvi, nonnunquam denticulato sen crenu- 

 lato. 



When I prepared my account of this genus for the second number of 

 my Genera of Recent and Fossil Shells, I had met with but few species, 

 and Lamarck who had paid much attention to the species had only de- 

 scribed twelve recent and two fossil. My acquaintance with them is at 

 present much more extended, and I now present my readers with an 

 account of twenty-five recent species. Still there is one species described 

 in Lamarck's Hist. Nat. des Anim. sans vert., namely, the O. hordeaceum, 

 which I have never yet seen : and I cim not quite satisfied about his 

 triticeum: as, however, I shall at some future time be obliged to pub- 

 lish an appendix to this genus, I trust I shaU then be able to give a good 

 account of the former, and to state a decided opinion respecting the 

 latter. 



The animal of this genus is still unknown to Naturalists ; there is, 

 however, strong reason to believe that it is nearly related to that of 

 Cyprcea, all the species being more or less covered with a shining 

 enamel-like shelly coat, evidently deposited by the bipartite mantle 

 spreading over the two sides of the shell, though seldom extending so 

 far over the back as nearly to meet and form a dorsal line as it frequently 

 does in Cypraa. The affinities of Ovulum appear to be on one side to 



'^ Ovulum, being a diminutive from Ovum which is neuter, our classical 

 friends will acknowledge the propriety of this change in the termination. 



