362 MOLLUSCA. 
specimens, the animal is quite black, the shell perfectly smooth, black 
and shining, with the apex always much recurved. [J. P. c.] 
Figure 463, lateral view of the animal and shell; 463 a, foot of the 
animal; 463 4, head of the animal in detail. 
D’Orbigny regards all the shells of this type found in the vicinity 
of Cape Horn as belonging to the same species. He says, “It inhabits 
all the southern region along the Atlantic shore, and for 12° along the 
Pacific coast. All the specimens from the Atlantic are nearly smooth, 
the summit elevated and very oblique; those from the Pacific, on the 
contrary, have quite well-marked ribs. All their other characters 
being the same, these differences do not seem sufficient to distinguish 
them specifically.” 
Mr. Couthouy, on the other hand, from careful examination of the 
shells and animals of numerous individuals, comes to a different con- 
clusion, and makes at least three species. We give them as deter- 
mined by his observations. 
SIPHONARIA ANTARCTICA (Couthouy MS.) 
Testa depresso-conica, oblongo-ovata, antrorsum angustata; apice sub- 
central, sinistrorsum inclinato ; striis radiantibus ad sexaginta in- 
sculpta, interstitiis castaneis: intus hepatica, margine pallido, crenu- 
lato ; angulo siphonali modico ; cicatrice valde impresso. 
Animat dull grayish or leaden colour, with rather sparse, prominent, 
pale yellow tubercles scattered over it; foot more oblong than in S. 
Lessoni, and of a clear ochreous yellow extending up some distance on 
its external margin. Head somewhat shorter and broader than in 
that species. But the principal specific distinction is in the position 
of the eyes, which are widely apart, about one-third the space from 
the lateral margin to the middle of the head, instead of the reverse. 
Mantle ochreous yellow, with brown marginal lineations correspond- 
ing to the indentures of the shell. 
SHELL rather depressed-conical, oblong-oval, narrowed anteriorly ; 
apex nearly median, sub-central, very slightly inclined to the left, sub- 
acute, usually somewhat eroded. Surface with from fifty to sixty 
