124 PROCEEDINGS OF THE ACADEMY OF [Feb., 
is always coarse on the cone, but on the cylindric part it may be coarse, 
partially effaced, or fine, in specimens of the same colony, while in 
some other colonies one or other of these conditions may be developed 
separately. The White Tail series deserves far more study than we 
have been able to find time for. 
The shell differs from H. cionella by the perceptibly longer taper 
and coarser striation of the terminal cone, and slightly greater develop- 
ment of the basal crest. In the form selected as type (pl. XIII, fig. 3) 
the ribs continue throughout, but in many examples of the same lot 
they weaken more or less on the penultimate and next earlier whorls. 
The callus within the aperture is very heavy. 
Type locality on the south side of the ‘‘box”’ of White Tail Canyon. 
Types (pl. XIII, fig. 3,) No. 99,684 A. N.S. P. It also was taken 
at Stations 1, 2, 3, 4, 5, 8, 14; most or all of these colonies being of 
considerable extent, although the gathering in each case was made 
in a small area. The highest points are at Stations 1, 3 and 8; the 
lowest in the Box Canyon and between Stations 14 and 13. See map 
on p. 75. It was taken also in Jhu Canyon, Turkey Creek and Lime- 
stone Mountain. All of these stations are on limestone. 
There is variation in sculpture in the type colony, some examples 
being strongly striate throughout, but in most the strie are weaker 
on the penult whorl. Pl. XIII, figs. 3, 4 and 5, represent shells from 
the type colony. Thirty-seven specimens of this lot opened measure: 
(Shells with the ribs weak on penultimate whorl.) 
One lamella: axial— 
Length 18, diam. 3.9 mm. 
Eo RO EV tin 
fe RY We gee arihe 
sh iG ie Isere 
Bee aed eta, gee oe 
ehh COM AG) to 
ce i Me ce 3.6 “ce 
cc 1, cc 3.4 ce 
ce 10, ce 3.8 ec 
a 10 sei. DRO, 
bf 
Two lamelle: axial and superior— 
Length 12.1, diam. 3.4 mm. 
ce 1 ce 3 ; 4 a3 
is3 10 (a9 3 ; 4 a3 
