1923} NATURAL SCIENCES OF PHILADELPHIA 73 
ochraceous buff with a slight cinnamon cast, whitish on the base, 
very little or not whitish alongside of the chestnut-brown band. 
There is generally no spiral striation, but sometimes the faintest 
traces may be seen below the last suture. The last whorl is wide 
and descends somewhat abruptly in front. The peristome expands, 
and in fully adult shells there is a slight thickening within. Par- 
ietal callus is very thin. Growth lines weak. The tip of the apex 
is smooth, followed by a few radial wrinkles, then some small 
papille near the suture. The rest of the embryonic shell has but 
little sculpture; small radial wrinkles below the suture are more or 
less noticeable, but no protractive or retractive threads. 
The genitalia were examined in specimens from stations 137, 138, 
146. The large penis is long, half the diameter of the shell or 
slightly more, sheathed at the base, and contains a large papilla, 
which is between half and two-thirds as long as penis, truncate or 
rounded at the end, where it is generally a little enlarged, and more 
or less wrinkled and dented. The penial retractor is less than half 
as long as penis, inserted on the epiphallus where the latter en- 
larges basally.4 There is a very small flagellum. Measurements 
follow. 
Museum No. 118108 118103 108099 118100 
Length of penis 12.5 12: 11.5 ace 
‘* papilla 8 8.5 6 7 
if * epiphallus 9 9 ve sere: 
ey ‘* retractor 5 5 
By ‘* vagina 12 
7 ‘ sp. and duct po en ee sree 
Station 146 146 138 137 
BV fig: 1 2 sre 3 
The form described and figured as S. ashmuni capax P. & F., 
taken by Frank Cole in the Cababi Hills, 1915, was not rediscovered 
in 1918. It is larger than any of the long series of ambigua taken, 
and the embryonic shell distinctly shows many protractive threads, 
of which we see no trace in S. ambigua. It is probably specifically 
distinct from the latter. 
The rather large caliber of the long penis and of the blunt papilla, 
generally larger at the end than further up, the penis longer than 
the epiphallus, are diagnostic of S. ambiqgua. The wrinkling of the 
papilla, doubtless due to contraction in alcohol, still in some degree 
depends upon its structure, and it varies to a certain extent in 
specimens from different mountain ranges. Unfortunately, no 
4In measuring penis and epiphallus, care must be taken not to include the 
thick basal part of the latter, below the insertion of the retractor, as part of the 
penis. The latter terminates at the root of the papilla, even when there is no 
distinct contraction above that point. 
