•II 
ELASMONEMA. 
273 
lamellar spiral striae. The aperture is circular, the lips are continuous, and the 
umbilicus rather large. As the name Gallonema had been used by Conrad in 1873, 
Fischer has substituted Elasnionema as the name for the genus. According to 
Fischer,^ these shells have been regarded by Lindstrom and by Meek as belonging 
to the Scalarid£e. He himself twice describes the genus, placing it first under the 
name of Elasmonema under the Scalaridae, and then under the name of Gallonema 
near the Trochidse. By ZitteP it is placed among the Trochidge. 
1. Elasmonema kotundum, n. sp. PL XXVII, fig. 5. 
Description. — Shell of moderate size, elevated, turbiniform, turrited, of about 
four rather rapidly increasing whorls. Spire conical, about half the height of the 
shell, rather more slender apically than below owing to the expansion of the body- 
whorl. Suture very deep and rather acute. Whorls very much swollen, sub- 
quadrate or step-like, of equal width and height ; in section spreading convexly 
out from the suture to the shoulder, then turning suddenly to the back, which is 
nearly flat, then again turning suddenly to the base, which is nearly flat, and then 
turning suddenly upwards to the umbilicus. Body- whorl comparatively larger 
and wider than the whorls of the spire. Ornament almost obliterated, but 
apparently consisting of very numerous, flat, parallel, close, spiral ridges divided 
by deep grooves. Umbilicus very large and deep, penetrating far up the centre of 
the shell. Mouth unseen. Shell-structure thin. 
Size. — Height 20 mm., width 18 mm. 
Locality. — Wolborough. A single specimen is in Mr. Vicary's Collection. 
Remarks . — The specimen from which the above description is taken is almost 
entirely a cast, but a few small fragments of the shell remain which show that 
the shell-structure is very thin, and that the cast closely represents the form of 
the external shell. The strise are visible to the naked eye, and were probably 
between twenty and thirty in number upon the body-whorl. 
Affinities. — This species is distinguishable from Gallonema Uchas, Hall,^ by 
having a wider shell, more quadrate whorls, and a larger umbilicus. 
1 1887, Fischer, ' Manuel Conch.,' pp. 778 and 836. 
2 1882, Zittel, ' Handb. Pal.,' pt. 1, Band ii, p. 188. 
3 1879, Hall, ' Pal. N. Y.,' vol. v, pt. 2, p. 52, pi. xii, figs. 19—22. 
