Zoology. 427 
any other, except £. subtilis, which, however, has considerably 
smaller and more warty spindles. 
If the locality be correct, it is remarkable as the only American 
species of a genus very common on the opposite coasts of the At- 
lantic. 
* 
= 
aQ 
ia) 
nm 
or 
ct 
x) 
= 
=) 
yr 
a 
oO 
~ 
=) 
ag 
2, 
=m 
i] 
i) 
=) 
if] 
i 
5" 
Qu 
i ool 
= 
5 
ta] 
a 
oO 
mt 
S 
o 
= 
i} 
io) 
if) 
<4 
oO 
nm 
oI 
oO 
BS 
Fa af 
BE 
om & 
=] 
+e 
ZF 
Qe 
23 
a 
ZS 
BS 
= § 
betes az 
oo 
TO 
Sa 
Bs 
ba 
oO = 
a 
S 5 
nie 
Ea = 
ao 
= & 
a 
ot 
Ex to 
DO 
of 
3 
So 
Bo 
ae 
ae 
= te, 
— pete 
Se 
gh wa Among them 
dles, double-spindles, double-heads, heads, and stout warty clubs, 
c 
most numerous, are short and thick, mostly with obtusely rounded 
ends, sometimes acute, median naked space narrow, bordered by 
e, coarse, rough warts, beyond which there are usu- 
i) 
many cases there are none between the median whorls and the 
terminal cluster, in other cases the whorls become crowded and 
thus the forms pass into large, stout “ double-heads,” in which the 
24, 
Mazatlan,—Voyage of the Venus. 
Am. Jour. Sc1.—SEconp Serres, VoL. XLVIL, No. 144.—Nov., 1869. 
29 
