438 PYKAMIDELLID^E. 



a light, horny, thin, obliquely- striated operculum, seated on a 

 simple lobe that is scarcely distinct from the upper part of the 

 foot near its junction with the body. 



Habitat as in the two preceding species. This animal is 

 now noticed for the first time. 



CH. SCALARIS, Philippi. 



Ch. scalaris, Brit. Moll. iii. p. 251, pL 94. f. 5 ; and (animal) pi. F.F. 



f. 5 ; and iv. pp. 274 & 277. 

 Ch. rufescens, Brit. Moll. iii. p. 253, pi. 94. f. 1 ; and iv. p. 274. 



Animal subhyaline-white, sometimes of a pale red muddy- 

 brown, aspersed with minute, opake, snow-white points, in- 

 habiting a white plicated shell of seven or eight volutions, 

 with transverse strise between the ribs, having the body 

 marked with two or three narrow, spiral, light reddish-brown 

 bands, and two on the penultimate volution; the apex is 

 strongly reflexed on its next neighbour. Mantle even, except 

 emitting a small cloven fold at the upper angle of the aper- 

 ture. Rostrum deeply notched in front, with the segments 

 gently arcuated. The tentacula are moderately long, strong, 

 and divergent, and exhibit the usual folding auriform phases 

 of their margins, but the varying inflations of the tips are 

 less developed than in many other species. The eyes are 

 black, not very close together, and fixed at the internal bases 

 of the tentacula, which do not entirely coalesce, being divided 

 by a distinct groove that is the continuation of one on the 

 rostrum from the point where the cleft terminates. The foot 

 is short, very slightly auricled, and on the march does not 

 extend much beyond the body volution, posteally declining to 

 an obtuse termination, at a little distance from which is the 

 almost simple upper lobe carrying the usual pyriform ellipti- 

 cally-striated operculum. * 



Habitat : shelly mud, in 10 fathoms water, six miles from 

 the shore, off Teignmouth, Devon. 



This animal has scarcely been observed, and the only obser- 

 vation as to colour does not quite accord with the live speci- 

 mens I have examined. I am now inclined to think, contrary 

 to my opinion expressed in the ' Annals of Natural History/ 



