BY C. HEDLEY. 501 



with indistinct brown dashes. Sculpture : the second or third 

 whorl develops a spiral keel, spiral threads appear first below, 

 then above it, later the sides flatten, then grow concave. About 

 the ninth or tenth whorl the adult sculpture is assumed, at and 

 after this stage the middle of the whorl is broadly constricted 

 between an upper and a lower prominent, spiral, rounded ridge. 

 The anterior cingulus usually splits in two on the later whorls. 

 Both ridges and constriction are ornamented with close, minute, 

 spiral threads. In turn these are overrun by close, thin, radial 

 lamella?, arcuate in the constriction, their edges making the shell 

 harsh to the touch. Base flat, inclining to concave, smoother 

 than the spire. Aperture subquadrate. Height 30mm.; breadth 

 7 mm. 



Several specimens from 16-20 fathoms. 



Judging from Reeve's figure the novelty most resembles 

 Turritella constricta^^" a species united (though probably errone- 

 ously) to T. clathrata Kiener, by Tryon.f T. captiva appears to 

 have more whorls in less length, to be narrower in proportion, 

 and to have the upper cingulus adjacent instead of remote from 

 the suture. 



Chossea inverta, n.sp. 



(Plate xvii., fig.l5.) 



Shell biconical, very solid, the ba.se produced, much exceeding 

 the spire, which is low and gradate. Colour milk-white. 

 Whorls four, the first minute, unsculptured, the others rapidly 

 increasing, parted by channelled sutures. Sculpture : the upper 

 whorls carr}'- three thick, elevated, spiral ribs, divided by broad, 

 deep grooves. These vanish on the last whorl, which is entirely 

 covered by dense, microscopic spirals so crossed by radials as to 

 give the eflfect of fine punctures over the whole surface. Basal 

 funicle massive, coiled on the body-whorl like a subsidiary whorl, 

 far extended anteriorly, its truncate extremity excavate. A 

 small perforation occurs below the aperture in the base of the 



* Reeve, Conch. leon.v. 1849, Turritella, pl.x. sp. 18. 

 tTryon, Man. Conch.viii. 18S6, p.206. 



