NO. 1264. ILL USTRA TIONS OF A MERICAN SHELLS— BALL. 545 
BOREOTROPHON DISPARILIS Dall.' 
This was described in 1891, from 52 to 77 fathoms, in the vicinit}' of 
Grays Harbor, Washington, and extends down the coast in deep water 
to the San Pedro channel. Possibl}^ a Trophonop^h. 
BOREOTROPHON TRIPHERUS, new species. 
Shell small, thin, delicate, white, with a thin j-ellowish periostracum . 
and a])out five whorls; nucleus eroded in all the specimens; early- 
whorls tabular, with about 14 low, sharp varices, sharply angulated, 
but hardly spinose on the shoulder, and growing feeliler on the sub- 
sequent whorls; below the shoulder are three feeble spiral threads 
which slightly undulate the varices; these threads grow feebler with 
age, and are hardly perceptible on the last whorl; aperture ovate, 
passing into the long, slightly twisted canal, which is strongly 
recurved; suture very distinct; outer lip thin, deeply flexuous behind; 
pillar thin, attenuated in front, twisted, with a pervious axis; oper- 
culum normal, pale brown; Ion, of shell 22.5; of spire without the 
nucleus 7; max. lat. of shell 9 mm. 
Dredged on the northwest coast by the U. S. Fish Commission steamer 
Albatross^ off Destruction Island, State of Washington, in 516 fathoms, 
mud, at station 3343, bottom temperature 38"^. 2 F. ; and at station 
3346, off' Tillamook Bay, Oregon, in 786 fathoms, bottom temperature 
37^.3 F.; U.S.N.M. 109044 and 109045. 
This interesting species belongs to the same group as B. scitulus Dall, 
and B. dlsparllis Dall, but is abundantly distinct from either of them. 
The development of spines, as in the former, is not a character of deep 
systematic import, and sometimes varies widelv in different individuals 
of the same species. These may perhaps belong in Trophonopiih. 
BOREOTROPHON ALASKANUS, new species. 
Shell creamy white with a more translucent substratum, the nucleus 
eroded, and five subsequent whorls; the whorls are rounded and bear 
eight narrow varices which are only prominent at the shoulder where 
they rise into long blunt spines which curve backward and somewhat 
toward the axis of the shell; there is no spiral sculpture, the incre- 
mental lines are not conspicuous, but magnification shows the surface 
when not eroded to be covered with a fine, sagrinate or subgranular 
sculpture, unlike anything I have noted on other species. The spire 
is elevated, the suture very distinct, the canal slender, long, and 
strongly curved ; the aperture is subovate, the pillar white and polished, 
the outer lip thin and slightly patulous opposite the base of the pillar; 
alt. of shell 32; of spire (nucleus missing) 12; max. diameter of shell, 
exclusive of the spmes, 14 mm. Operculum normal, dark brown. 
I Figured in Proc. U. S. Nat. Mus., XVII, 1895, pi. xxvii, fig. 4. 
Proc. N. M. vol. xxiv— 01 35 
