Comprehensive Description

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Trophon longstaffi.


(Pl. I., figs. 3-3d.)



Shell ovately fusiform, white, rather thin, longitudinally delicately plicate; whorls 6-7, the two apical forming the protoconch(fig. 3b.) globose, smooth, glossy; the rest convex, rather shouldered above, separated by an oblique deep suture, ornamented with numerous thin lamellæ, which are directed forward, and often somewhat produced at the upper part, especially upon the body-whorl. They vary in number from 10 to 20 upon the last whorl, but generally average about 16. The surface is also sculptured with very fine spiral striæ both between the lamellæ and upon their upper surface, but their lower is smooth. The last whorl is contracted below and produced into a short oblique snout which is directed towards the left. The aperture is pear-shaped, with the canal considerably longer than the spire, smooth and white within. The outer lip in the most adult specimen is a little thickened within, sharp at the edge, and somewhat patulate and united above, with a distinctly defined callosity which covers the columella. The anterior canal is short and oblique.


Length, 41 millim.; greatest diameter, 25.5; aperture, with canal, 25 millim. long, 12 broad.


Flagon Point, 1 mile N. of ship, 20 fathoms; holes 4, 12, in 25-41 fathoms.


The animal externally appears to be normal, the tentacles are short, compressed, pointed at the tip, with the minute sessile eyes situated about midway upon the outer edge. The operculum (figs. 3c., 3d.) is elongate-ovate, rather thin, of a reddish horn colour, slightly convex externally, marked with distinct lines of growth from the apical nucleus, and also exhibiting a few arcuate rays, which curve from the apex to the inner margin. The lower concave surface is finely wrinkled, with a broad, glossy, reddish and


somewhat thickened margination on the outer edge, and is dull upon the rest of the surface.


This species does not compare closely with any of the described forms. Perhaps the Patagonian T. laciniatus is its nearest relation. It is, however, rather different in form, its whorls are broader, and the lamellæ are not produced above into hollow spine‑like projections. The aperture also is devoid of the orange or brown colour which distinguishes the South American shell.”



(Smith, 1907: 3)


Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© National Museum of Natural History, Smithsonian Institution

Source: Antarctic Invertebrates Website (NMNH)


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