GASTEROPODA. | DEVONIAN MOLLUSCA 399 
slightly oblique, anterior half of columella thickened, flattened, posterior half often deficient ; surface smooth or 
marked by fine lines of growth. 
Allied to Zoxonema, but much shorter, more ventricose, with larger body-whorl, smoother surface, and wide 
ovate mouth. 
MACcROCHILUS VENTRICOSUS (Gold. Sp.) 
Ref. and Syn.—Buccinum acutum Sow. Geol. Trans. 2nd Series, Vol. V. t. 57. f. 28. (not Min. Con.) = Maero- 
chilus imbricatus Phill. Pal. Foss. f. 1945. (not Sow. Min, Con.) = Phasianella ventricosa Gold. Pet. 
Germ. t. 198. f. 14.= Macrochilus subimbricatus @Orb. Prod. Pal. p. 63. 
Sp. Ch.—Ovate, spire slender, of about five or six whorls; apical angle about 60°; body-whorl abruptly 
wider than the spire, rounded; whorls of spire moderately convex, most so below the middle; surface marked 
with sharp, nearly direct lines of growth. Length nine lines, proportional length of body-whorl 7, length of 
penultimate whorl =, width of body-whorl 4, width of penultimate whorl %. 
The greater abrupt convexity of the middle portion of the body-whorl, and the contracted, more slender 
spire, easily distinguish this species from the carboniferous Buccinwm imbricatum or acutum (Sow.), with which 
it has been confounded. 
Position and Locality—Common in the Devonian limestone of Plymouth. 
Genus. LOXONEMA. See page 502. 
LOXONEMA NEXILIS (Sow. Sp.) 
Ref. and Syn. = Terebra neuilis Sow. Geol. Trans. 2nd Series, Vol. V. t. 54. f.17. = Terebra arcuata 
Munst. Beitr. 1840. t. 15. f. 2. 
Sp. Ch.—Very elongate, conic; apical angle 17’; whorls about ten, slightly convex, most so below the 
middle ; sutures deep, simple; surface fluted with backward-arched, longitudinal, slightly irregular strize, about 
eight in the space of one line, at a diameter of two lines. Average length eight lines, proportional length of 
body-whorl about ;;, length of penultimate whorl 2, width about %. 
There can be little doubt that the smaller of the two specimens figured by Sowerby is distinct from the 
large one, which I choose for the type of the species, having much thicker, straighter, and fewer longitudinal 
costee. I should think the S. Petherwin shell figured and described by Phillips, Pal. Foss., as the Silurian 
Terebra sinuosa of Sowerby, belongs to the present species. 
Position and Locality —Not uncommon in the limestone and shale of S. Petherwin. 
