MOLLUSCA. 41 



with four plaits, the upper being somewhat distant, and the lower not very dis- 

 tinct. The outer lip is thin, and uneven by reason of the sulci which terminate 

 on the margin ; the inner is slightly developed. 



Imbricaria. Schumacher. 



Imbricaria, Schumacher, 1817. Conohelix, Swainson, 1833. 



169. Imbricaria carbonacea, (Plate XI, fig. 9, 10.) Testa, conico-involula, laevigata, polita, 

 nigerrirna, prope basin obsolete sulcata; spira acuminata; columella quinque-plicata; plicis gra- 

 datim minoribus, inferioribus subobsoletis. 



Inhab. L'Agulhas Bank, Cape of Good Hope. Dredged from deep water, on 

 a gravelly floor. 



Cancellaria. Lamarck. 



170. Cancellaria ventricosa, Hinds, Proceed. Zool. Soc. 1843, p. 47, (Plate XII, fig. 11. 

 12.) Testa ovata, acuminata., albescente ; anfractibus septenis, ventricosis, subturbinatis, cancel- 

 latis, interstitiis quadratis ; apertura oblonga, prope mediam dilatata. ; labio interno expanso; colu- 

 mella triplicata; umbilico mediocri. 



Inhab. The west coast of America, between 12° 28' and 24° 38' north latitude ; 

 viz. Realejo, in from sixty to seventy fathoms ; San Bias ; Gulf of Magdalena, 

 California, in seven fathoms, sandy mud. 



Very similar in its characters to C. Candida, but distinguished from it in the 

 absence of the secondary impressed lines which cross and interfere with the can- 

 cellation. C. Candida is described with only two columellar folds, which might be 

 regarded as another source of difference, our shell having three very distinct. 

 But I think it will be found on close examination that the former has a third 

 incipient fold, which, though very small, truly exists. 



171. Cancellaria urceolata, Hinds, 1. c. p. 47, (Plate XII, fig. 7, 8.) Testa ovata, acumi- 

 nata, laevigata, epidermide fusca induta. ; anfractibus septenis, costatis, superne subangulatis, ultimo 

 subquadrato ; costis parviusculis, rotundatis, lineis elevatis decussatis ; apertura oblonga, in canalem 

 recurvum effusum desinente ; labro subrecto, intus sulcato ; labio interno expanso ; columella bipli- 

 cata, sed plica tertia inferiore obsoleta ; plica superiore in dente acuto desinente, sinu inferiore 

 magno ; umbilico parvo. 



Inhab. The west coast of America, between 12° 2' and 21° 32' north latitude ; 



M 



