Mr. W. Clark on some of the Animals of the Chemnitzise. 201 



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 elliptically 

 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 specimens 

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

 opinion in the 'Annals,' N. S. vol. vii. p. 387, that there are two 

 varieties of this species : the one scalar, or with turreted sub- 

 angular volutions, which is considered the type, under the title 

 of Chemnitzia scalaris ; the other, with rounded volutions, has 

 the specific appellation of C. rufescens. I have taken both 

 alive, and could detect no difference in the animals, except in 

 colour; the C. scalaris being sometimes subhyaline frosted white, 

 at others pale red-brown, and the same variations attend the so- 

 called C. rufescens. I may be in error as to the identity of the 

 two, but that is my present impression. 



Aug. 10th. — I this day took at the same haul two shells, one 

 of which proved the typical C. scalaris, the second was the form 

 termed by authors C. rufescens ; they were both put in a vase, 

 and being lively, I again saw that their organs were identical. 



Chemnitzia fenestrata, auct. 



Animal inhabiting a longitudinally plicated and spirally ridged 

 white shell of eight rather flat volutions which bevel from their 

 bases to the sutural lines ; the apex has the usual reflexion of 

 the tribe. The general colour of the external organs is a sub- 

 hyaline frosted white, the internal posterior volutions are a deep 

 red-brown. Mantle even with the aperture, except a small shoot 

 at the upper angle. Rostrum slender, long, flat, barely hollowed 

 at its termination. The tentacula are comparatively long, slender, 

 and fold after the characteristic manner of the race, and have 

 the white inflated tips ; they are united at the bases, on which, 

 close together, are imbedded at the internal angles the conspi- 

 cuous black eyes. The foot in slow march is short, broad and 

 obtuse, but when the pace is accelerated it attenuates and ex- 

 tends to the bottom of the second basal volution ; anteriorly it 

 forms a concave sweep, ending on the right and left in very 

 slight auricular points, and posteriorly in a moderate lanceolate 

 shape, carrying on a simple lobe, close to its junction with the 



