BUCCINUM HYDROPHANUM. 103 



the contrar}^ are strongly plicated, Avliile in the fourth the whorls are tumid.' 

 Dv. Nordmanu informs me that in the museum at Copenhagen there are a series of 

 specimens under the present name, the extreme forms of which are different, but 

 that they are connected by intermediate varieties. He has been kind enough to send 

 me a typical specimen of one of them which I here figure. It agrees more or less 

 nearly with some special forms of my Oakley fossils, which appear to be different 

 from anything else in my collection. Without expressing any definite opinion on 

 the question of nomenclature, and as there seems some doubt with which species 

 my Crag shells should be grouped, I figure one of them provisionally as B. perdix. 

 In the convexity of its whorls it corresponds closely with one of Posselt's figures. 



Buccinum hydrophanum, Hancock. 



1846. Buccinum hijdroplianum, Hancocli, Aim. Mag. Nat. Hist., vol. xviii, p. 325, pi. v, fig. 7. 



Var. tumidula, Gr. 0. Sars. Plate IX, fig. 9. 



1847. Buccinum hydrophatnim, Reeve, Concli. Icon., vol. iii (Buccinum), pi. xiii, fig. lOo. 

 1878. Buccinum tumidulum, G. O. Sars, Moll. Reg. Arct. Norv., p. 263, pi. xxv, fig. 5. 



1882. Buccinum liydro})lianum, var. tumidula, Friele, Norske Nordh. Exped. (MoUusca), pt. i, p. 31, 

 pi. iii, fig. 21. 



1883. Buccinum tumidulum, Kobelt, Martini und Chemnitz, Conch. Cab., ed. 2, vol. iii (Buccinum), 

 p. 49, pi. Ixxxiii, fig. 6. 



1887. Buccirium tumidulum, Kobelt, Icon, schalentrag. europ. Meeresconch., vol. i, p. 106, pi. xix, 



fig. 10. 

 1899. Buccinum hydroiAanum, var. tumidosa, Posselt, Medd. om G-ronl., vol. xxiii, p. 208, pi. ii, fig. 13. 

 1912. Buccinum hydrophanum,, Dautzenberg et Fischer, Camp. Scient. Pr. Monaco, vol. xxxvii 



(Mollusques), p. 135, pi. viii, fig. 18. 



Varietal Cluiraders. — Shell thin and fragile, ovato-fusiform, whorls 6 or 7, 

 decidedly convex, the last ventricose, two-thirds the total length ; suture deep, 

 mouth nearly half the length of the shell ; outer lip thin, regularly rounded; inner 

 lip forming a wide glaze upon the pillar; surface smooth, covered with very fine, 

 irregular and inconspicuous spiral striae but without longitudinal plications ; canal 

 short. 



Dimensions. — L. -18 mm. B. 25 mm. 



Distribution. — Recent : Finmark, Iceland, Greenland, Davis Strait ; generally 

 throughout Arctic Seas. 



Fossil : Waltonian Crag : Little Oaliley, very rare. 



1 Prof. Kobelt regards B. perdix as a variety of B. grcenlandicum (Icon, schalentrag. europ. Meeres- 

 conch., vol. i, p. 113), as did Morch. Prof. G. 0. Sars, on the other hand, considers it a synonym of 

 B. finmarchianum. To some extent our shells approach one of the varieties of B. meridionale ; 

 the latter, however, is a Newfoundland species, while this is Scandinavian, and has a shorter mouth. 



