714 PROTOCONCHS OF CERTAIN PORT JACKSON GASTEROPODA, 



grown specimens with their apices on being rare. It has occurred 

 to me that this apex, like that of Scaphella, may have been 

 deposited inside an original corneous one which was discarded 

 in, or soon after the mollusc left, the egg-capsule.* The above 

 measurements of the protoconch are taken from the specimen 

 figured. 



SiSTRUM NEGLECTUxM, Angas. 



(Plate xxxvi., fig. 2.) 



Apex thin, semi-pellucid, polished, devoid of sculpture and epi- 

 dermis, of about one and one-half whorls. The protoconch is not 

 sharply defined, but the acquisition of a slight sculpture suggests 

 the termination of the embryonic structure Dimensions of the 

 specimen figured, length 3, breadth 1 -5 mm. 



Capulus violaceus, Angas. 



(Plate XXXV., figs. 7-9.) 



Apex of a little more than one whorl, devoid of an epidermis, 

 thin, brown, smooth, shining. The specimen figured shows a 

 division between the embryonic whorl and the succeeding adult 

 whorl; this is not always present. I have seen specimens which 

 show no such division. Fig. 9, pi. xxxv., represents the ananeanic 

 sculpture from a specimen slightly older than the one figured. 

 The embryonic structure is defined by the acquisition of sculpture. 

 Greatest diameter of the protoconch 1 mm. 



LiOTiA clathrata, Reeve. 

 (Plate xxxv., fig. 6.) 



Apex of one whorl, slightly depressed, thin, smooth, white, semi- 

 pellucid, shining, defined by the acquisition of sculpture. Greatest 

 diameter of protoconch 1 -5 mm. 



The neanic structure of this species is perhaps more interest- 

 ing than the protoconch. So unlike the full grown shell is it 



* See Ball, Bull. Mus. Comp. Zool. Harvard Coll., Vol. xviii., 1889, p. 452. 



