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Genus 2. TEREBELLUM, Lamarck. 



Animal ; unknown. 



Shell ; cylindrically elongated, spire acuminated, last whorl slightly 

 inflated towards the base, where it is abruptly curtailed and 

 emarginated; columella smooth, produced at the base; lip simple. 



Although the Terebellum shell was known to Klein, Lister, and one or 

 two other writers antecedent to Lhmseus, and is not unfrequently collected 

 on the shores of the eastern seas, no specimen has yet been found with its 

 molluscous inhabitant. It is of a very isolated form, intermediate, in a man- 

 ner, between Conus and Bulla, to both of which genera Linnajus at different 

 times referred it in ' Systema Naturae/ Sowerby in his ' Genera of Shells ' 

 considers the Terebellum most nearly allied to St ro ml us, I do not think, 

 however, that will prove to be the case ; there are certainly one or two species 

 of the latter in which the shell bears a striking resemblance to the former, 

 but there is a peculiarity in its light Bulla-like convolution which inchoates 

 the presence of a very different animal from that of Strombus • though 

 probably one of equally remote affinity with either Conus or Ovidum. 



Terebellum subulatum. Plate 1. Fig.6. From Mr. Cuming's collection. 



Genus 3. OVULUM, Bruguiere. 



Animal; disc ample, oblong-ovate, somewhat acuminated at the 

 ends, in slight folds ; head somewhat obscure, with the siphonal 

 appendage produced into a broad wrinkled fold ; tentacles long 

 and stout, eyes situated ujjon a prominent subramose thickening 

 at about the middle ; mantle extended on each side into a lobe, 

 sprinkled 'with short spinous processes, envelopi?ig the shell. 



Shell; oval or oblong, smooth, more or less produced at the extre- 

 mities ; spire concealed; aperture longitudinal, columella smooth, 

 lip mostly thickened and inflexed, sometimes wrinkled ; pure 

 white, sometimes pink or violet tinged. 



There is so close an affinity between the animals of Ovulum and Cypraa, 

 especially between the 0. ovum and the C. Mauritiana, that it would lie im- 

 possible to refer them to separate genera were it not for the marked dif- 

 ference in the shells. M. De Blainville proposed, in conformity with this 

 resemblance of the soft parts, to regard the Ovuli as merely a section of 

 the genus Cypraa ; it is certain, however, that animals producing two such 



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