948 PROCEEDINGS OF THE NATIONAL MUSEUM. WO LOCIG i 
name rhines. All belong to the subgenus Surcula, though not to its 
typical group. The following form is close to P. ophioderma, and 
for some time was regarded as a slender variety of it. The examina- 
tion of a number of specimens and their constancy in character lead 
to the conclusion that it 1s a distinct species. 
TURRIS (SURCULA) HALCYONIS, new species. 
Shell small, slender, very acute, of a livid purple covered with an 
olivaceous periostracum, with about eleven whorls; nucleus more or 
less eroded, but apparently smooth, acute, and including about two 
and a half whorls; subsequent whorls rather flat, compressed and 
appressed at and in front of the suture, with a rounded base and 
inconspicuous anal fasciole; sculpture chiefly of flattish spiral 
threads, one at the suture, three smaller ones in front of it, followed 
by a flat broader one representing the fasciole, then (on the last 
whorl eight) more prominent threads, undulate or segmented by in- 
cremental lines and with wider interspaces (sometimes containing an 
intercalary smaller thread) to the base, followed by six or seven 
unsegmented threads to the siphonal fasciole, which bears six or seven 
smaller threads; the succession of undulations or shghtly swollen 
seoments gives a slightly cancellate effect to the part of the whorl 
which bears them, but there are no axial ribs, the effect being pro- 
duced rather by depressions between the rather coarse incremental 
lines; aperture narrow, acute behind, the anal sulcus narrow and 
distinet but not very deep, the outer lip in front of it arcuately pro-. 
duced, the canal contracted, short, and recurved; inner lip polished 
and superficially erased; the pillar twisted, with a thin layer of cal- 
lus; eperculum present as in 7’. ophioderma. Height of shell 23.0; 
of last whorl, 12.5; of aperture and canal, 8.0; maximum diameter, 
7.0 mm. 3 
Type.—Cat. No. 110644, U.S.N.M. Off Coronado Beach, San Diego, 
in 10 fathoms, Professor Kelsey; San Pedro, various collectors, 
Genus ACANTHINA Fischer. 
(Monoceros Lamarck.) 
ACANTHINA LAPILLOIDES Conrad, new variety AURANTIA Dall. 
The usual color of A. lapilloides is grayish, with a bluish or pur- 
plish tone and small brown maculations, but Dr. R. H. Tremper has 
collected an orange-yellow color variety on rocks at San Pedro 
which almost exactly mimics the yellow form of Purpura (=Thais 
Bolten) decemcostata. It is slightly smaller on the average than 
the ordinary /apilloides, with the interspaces of the spiral threads 
prettily lamellose axially and more or less articulated with blackish 
