266 MR. E. A. SMITH ON THE [Apr.), 



longit. totius k cequans ; lahrum leniter incrassatum, intus den- 

 ticulatum ; columella triplicata. 

 Longit. 5 millim., diam 2\. 



This species at first sight looks very like the shell previously 

 described as Pleurotoma multigranosa, but, of course, is perfectly 

 distinct. It is remarkable for its small size, the minutely beaded 

 ribs, the dark apex, and the style of coloration. Allied to M. albo- 

 cincta, C. B. Adams. 



MiTRA (Thala) pleurotomoides. (Plate XXIII. fig. 10.) 



Testa parva, hreviter fusiformis, albida, interdum biteo-tincta ; 

 anfractus sex., duo supremi Iceves, superne acute carinati, plant, 

 quasi truncati, cceteri convexiusculi, costis longit udinalibus 

 circiter 16, lirisque transversis {in anfr. penult. 5-H, in ultimo 

 1 8-20) granose clathrati ; apertura parva, angusta, longit. 

 totius I ndcequans ; labrum leviter inc?-assatum, denticulis circiter 

 sex intus munitum, postice distincte sinuatum ; columella rec- 

 tiuscula, leviter obliqua, in medio plicis duobus instructu, callo 

 tenui superne labro juncto induta. 

 Longit. 5 millim., diam. 2. 



This species is remarkable for the peculiar truncate apex, the 

 Pleurotomoid labral sinus, and the columellar plaits being tvpo only 

 in number. Fischer (Man. Conch, p. 612) has pointed out that 

 Mitras of the group Thala have much affinity with the shells of 

 Clathurella and Mangilia. I might point out that one species, 

 Thala solida, was described by Reeve ' as belonging to the latter 

 genus, and another, Thala todilla, was originally published by 

 Mighels^ as a species of Pleurotoma. It therefore still remains 

 doubtful to which family, Pleurotomidce or Mitridte, this group 

 should be referred. 



Marginella (Volvaria) cinerea, Jousseaume. 



The type of this species, M. semen of Reeve, not of Lea, described 

 by Reeve (Conch. Icon. pi. xxvi. fig. 145), is now in the Museum, 

 having been presented by Mrs. Lombe Taylor after the death of her 

 husband. It is incorrectly said by Reeve to have four plaits on the 

 columella, for on careful examination only three are discernible, 

 nor is this number exceeded in any of the specimens, nearly twenty 

 in number, from St. Helena. Reeve's figure does not accurately 

 represent the form of the spire, and the sutural line is too low down. 

 No locality has previously been quoted for it. 



Marginella (Volvaria) consanguinea. (Plate XXIIl. 

 fig. 11.) 



Testa minuta, ovata, alba., nitida, pellucida ; anfractus 3-4 ; spira 

 brevissima, obtusissime conica ; anfr. ultimus elongate ovutus, in 

 medio labri levissime constrictus ; apertura angustissima ; 

 labrum paulo incrassatum, inflexum, urcuatum, intus Iceve, 



^ Couch. Icon. (JSIangclia), sp. 64. 



'^ Proc. Bost. Soc. Nat. Hist. 1845, vol. i. p. 24. 



