MUSEUM OF COMPARATIVE ZOOLOGY. 407 



dos, in 84-154 fras. Coast of Portugal, in 286-322 ims., Porcupine Expedition. 

 Sicilian Tertiaries, Seguenza, etc. 



All the specimens obtained were dead. I have compared them with the 

 Sicilian fossils, and can confirm Dr. Jeffreys's identification of the two forms 

 as indistinguishable. The whole shell is faintly spirally twisted, and the 

 notch is not in the centre of the front edge. 



I would observe that the number of nominal species of Emarginula in 

 Reeve's monograph is probably far too great, as no account seems to have been 

 taken of the variations due to age and station. As with other limpets, these 

 are very important. 



Subgenus SUBEMARGINULA Blainville. 



Subemarginula octoradiata Gmelin. 



Emarginula Rollandi Dall, Bull. M. C. Z., IX. p. 77, 1881 (not of Fischer). 



Habitat. Sigsbee, off Havana, in 450 fins. Station 21, 287 fms. 

 The dead and imperfect specimens above referred to, on further study, ap- 

 pear to be young specimens of E. (Subemarginula) octoradiata Gmelin. 



Genus FISSURELLA Brugciere. 



Section CREMIDES H. & A. Adams. 



Fissurella alternata Sat. 



Fissurel/a alternata Say, Journ. Acad. Nat. Sci. Phila., II. p. 224, 1822. Reeve, 



Conch. Icon. Fissurella, pi. xii. fig. 84, 1850. 

 Fissurella fumata Reeve, Conch. Icon. Fissurella, pi. ix. fig. 63, 1850. 

 Fissure/la Dysoni Reeve, Conch. Icon. Fissurella, pi. xii. fig. 86, 1850. 

 Fissurella larva Reeve, Conch. Icon. Fissurella, pi. xiii. fig. 98, 1850. 



A number of specimens of this species were collected at various stations, one 

 in 805 fins., but of course these were not native to that or other great depths. 

 Fresh specimens, however, were dredged by Sigsbee, off Havana, in 80 fms., 

 and one still containing the soft parts at Station 276, near Barbados, in 94 fms. 

 The United States Fish Commission has also dredged this species off our south- 

 ern coasts, living in depths from 20 to 100 fms. The deep-water specimens 

 (var. Sayi) are generally smaller, of an olivaceous cast, and with the color 

 rays very faint or entirely absent. 



