348 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 53. 



"Found in coarse sand at a depth of 13 fathoms." 

 I have not seen specimens of this species and copy Sowerby's 

 description and figure. 



Genus NISO Risso. 



Niso Risso, Hist. Nat. Eur. Merid., vol. 4, 1826, p. 218, p. 7, fig. 98; type 

 Niso eburnea Hiaao—Bonellia Deshayes, Lamarck's Anim. sans. Vert., vol.8, 1838, 

 p. 286; Type Bonellia terehellata Deshayes {=Bulimus terebellatus Lamarck)= 

 Janella Grateloup, Conch. Foss. Adaur., 1838, p. 12; Type Bulimus terebellatus 

 Lamarck= FoZwsia A. Adams, Ann. Mag. Nat. Hist., ser. 3, vol. 8, 1861, p. 306; 

 Type Volusia imbricata Sowerby. 



Melanellids having the base broadly uml)ilicated . 



NISO SPLENDroULA Sowerby. 



Plate 48, fig. 5. 



Eulima splendidula Sowerby, Proc. Zool. Soc, 1834, p. 6, = Niso splendidula 

 Sowerby, Thes. Conch., 1854, p. 801, pi. 170, fig. 8. 



This species is described by Sowerby as acuminately pyramidal, 

 brownish, articulated near the sutures with white and chestnut; 

 umbilicus large. Aperture anteriorly angulated. 



Sowerby's specimen was collected by Cummings at Santa Elena, 

 Ecuador, on sandy mud in 6 to 8 fathoms. The type, figured by 

 Sowerby, has 18 whorls and measures— length, 38 mm.; diameter, 

 17 mm. It is the largest known from the west coast of America to 

 date. 



Cat. No. 251334, U.S.N.M., contains a very badly worn and frag- 

 mentary specimens of this species, which was dredged by the U. S. 

 Bureau of Fisheries steamer Albatross in the Bay of Panama at 

 station 2798, in 18 fathoms on gray sand and broken shell bottom. 



NISO EXCOLPA, new species. 



Plate 48, fig. 4. 



Shell broadly elongate-conic, mdely and openly umbUicated , flesh- 

 colored, with irregularly interrupted axial bands of brown immediately 

 behind the varices, and faint spiral bands. The junction of these 

 produce the intensified color markings, and the Ughter areas between 

 hem give the axial markings the interrupted aspect. Umbihcus 

 purple, extreme tip of the shell white. Early v/horls well rounded, 

 the later ones flattened, marked by strong lines of growth only. 

 The appressed summit of the whorls falls a little anteriorly to the 

 periphery, and causes the preceding whorl to have an over-hanging 

 appearance. Periphery of the last whorl strongly angulated. Base 

 moderately long, well rounded; mnbilicus about one-sixth of the 

 greater diameter of the shell. Aperture rhomboidal, decidedly 

 angulated at the junction of the inner and basal lip, somewhat 

 less so, at the junction of the basal and outer lip; posterior angle 



