OF CONCHOLOGY. 105 



Habitat of the variety, Sitka, Alaska Territory, in abundance, 

 Dall and Bischoflf. 



The Volutharpa Mosrchiana, Fischer, (Journ. de Conchyl. 

 vii, p. 299, Mar., 1859,) is, without doubt, a depressed variety 

 of the No rth Pacific form of Buccinum cyaneum, Brug. This 

 has been confirmed by the examination of specimens, but is suf- 

 ficiently evident from the very good figures in the Journal de 

 Conchyliologie. 



Apropos of this species, M. Fischer observes that it forms a 



passage from Volutharpa to Buccinum, which, as far as the shell 



is concerned, is quite true, except that the suture is not canali- 



culated, which alone, conchologicalW, would remove it from 



Volutharpa, all the forms of which have a channelled suture. 



The Volutharpa Perryi is insufficiently described and figured, 

 yet appears specifically different from the ampullacea. The 

 dimensions are not given, but if the figure be of natural size, it 

 is much larger than that species. 



Although M. Fischer expresses doubts as to the validity of 

 his genus, in vieAv of the differences of the ovi-capsules, denti- 

 tion and soft parts, it must be considered as well sustained, 

 after eliminating the stranger whom he had inadvertently ad- 

 mitted. 



Troschel (Geb. der Schn. ii, pi. vi, f. 14) figures the dentition 

 of a species which he refers to V. Perryi. It differs in some 

 particulars from that of Buccinum. He also states that the 

 animal was without an operculum. Other authors do not men- 

 tion an operculum. 



With regard to the V. ampullacea, a very remarkable fact 

 may be mentioned. The majority of the individuals are without 

 opercula, even without a trace of the pad-like gland or area from 

 which the operculum is secreted. About ten per cent, of the 

 individuals of the var. acuminata which I have examined had 

 traces of this gland or area, marked by its smooth and rather 

 whitish surface on the granulous dark slate colored foot. About 

 fifteen per cent, had well developed opercula in the proper posi- 

 tion. I have ascertained the same to be the case with regard to 

 the typical form, from alcoholic specimens, collected by Dr. 

 Stimpson in Behring Strait. There is no mistake about this, 

 strange as it may and must appear, that different individuals of 

 the same species are indifferently operculate or inoperculate. 



A careful examination of this appendage reveals some singu- 

 larities in it worthy of note. At first the operculum is of an 

 ovoid form, with the nucleus near the edge at the larger end, 

 and increases by additions around the edge, but principally upon 

 the smaller or upper end. However, at some late period of its 



