214 PROCEEDINGS OF THE AATIONAL MUSEUM. vol.54. 



Atractus Agassiz, Min. Conch., German ed., 1840, p. 44. Types, Murex 

 striatus (= antiquus Linnaeus) and M. contrarius Gmelin. Not Atrac- 

 tus Wagler, 1828. 



Neptunea Morch, Cat. Yoldi, 1852, p. 104. (First species, Murex antiquus 

 Linnaeus). Not of Renier, 1847. 



Chrysodomus Cossmann, Essais de Pal. Comp., livr. 4, 1901, p. 98. Type, 

 Murex despectus Linnaeus. — Dall, Proc. U. S. Nat. Mus., No. 1264. p. 

 520, 1902. 



Neptunea Dautzenbeeg and Fischeb, Res. Camp. Scientifiques de Monaco, 

 livr. 37, 1912, p. 68.— Habmer, Pliocene Moll. Gt. Brit., pt. 1, p. 156, 

 1915. Not Neptunia Renier, 1847 (Coelenterata). 



The name Neptunea Bolten was given to a heterogeneous collec- 

 tion now divided into eight or more genera of several distinct 

 families. Link in 1807 segregated Nassa without accepting La- 

 marck's name for it, which had already been used by Bolten for a 

 different group. Bolten selected no type and gave no diagnosis. One 

 by one the species included in his genus were used as types for new 

 genera by later authors. The name generally accepted for the present 

 group and including F^isinus Rafinesque, was Fusus Bruguiere, 1789, 

 but not of Helbling, 1779. 



In 1840 Swainson instituted the genus Chrysodomus and men- 

 tioned as typical example (p. 90) the "beautiful orange mouth wilk 

 of England " {Fusus antiquus). The first species of his list given on 

 a later page is C. dispectus (sic), the second C. argyrostomus {= O. 

 antiquus). Both are unquestionably congeneric, and the former, 

 Murex despectus Linnaeus, has been taken as type by several authors 

 who probably did not notice the selection of a type on the earlier 

 page. 



Shell large, short-fusiform, smooth or spirally sculptured, some- 

 times with rude axial ribbing or nodosities or varixlike sharp 

 laminae ; outer coat of the shell subtranslucent, the inner layers with 

 a darker, usually purplish tint, the periostracum inconspicuous 

 imd dehiscent: last whorl longer than the spire, with a wide aperture, 

 the outer lip in the adult flaring or subreflected, not thickened ; pillar 

 flexuous, smooth ; labium without callosities or lirae ; inner side of the 

 outer lip without liration in the typical group; the canal rather 

 long, wide, open and flexuous; animal short and broad; the penis 

 large, usually sickleshaped and with a small elongate terminal 

 papilla; operculum ovate with apical nucleus, nearly closing the 

 aperture ; ovicapsules massed, sessile either in a heap as in Buccinum, 

 or in a cylindrical erect group ; nucleus submammillary, of the Chryso- 

 domoid type hereinbefore defined ; the subsequent whorls rapidly in- 

 creasing, not numerous. The dental formula 1. 1. 1, the teeth usually 

 tricuspid, the central rhachidian cusp and outer lateral cusps usually 

 larger; the minor cusps often irregular, multiple or obsolete. The 

 habitat of the genus is in cold water of the North temperate or Arc- 

 tic seas. 



