234 TURBONILLID A. 
Syn.—Michelia, Romer. Holopella, Sandb. (in part). 
Distr.—Fossil, 75 sp. L. Silurian—Trias; North America, 
Europe. JL. costatuwm, Sandb. (Ixviii, 97). 
Shell elongated, many-whorled ; aperture simple, attenuated 
above, effused below, with a sigmoidal edge to the outer lip. 
Like many other paleozoic genera, the bad condition of many 
of the species and the variation in form and sculpture render it 
difficult to place it properly in a systematic work; some of the 
species might go into Turbonillide, others appear closely allied 
to Chemnitzia, and might even be synonymous with it. 
OrTHONEMA, Meek and Worthen, 1861. 
Distr.—Several fossil species. Devonian, Carboniferous; U.S. 
O. Salteri, Meek. 
Shell elongate, many-whorled; volutions ornamented with 
revolving carine, crossed by nearly straight lines of growth ; 
body-whorl not produced below ; aperture angular above, slightly 
effuse below ; peristome incomplete ; lip simple, nearly straight ; 
axis imperforate. 
Differs from Turritella in its slightly effuse and less rounded 
aperture, disconnected peristome, and straight outer lip. It is 
probably more nearly allied to Loxonema, but has distinct 
revolving carine, and wants the sigmoid outer lip of that genus. 
BourauetiA, Desh. 
Distr.—Phasianella striata, Sowb., ete. Jurassic. 
Shell large, turreted; spire long, pointed; whorls convex, 
spirally striated or orooved ; last whorl large ; mouth oval, 
angular behind, widened and rounded i in front. 
Famity TURBONILLID. 
Animal with a short head, triangular tentacles, and eyes at 
their outer bases; proboscis long, retractile ; foot truncated in 
front. 
Shell white, slender, elongated, many-whorled, mostly longi- 
tudinally ribbed or spirally striate. Opereulum horny, sub- 
spiral. 
The animal differs from that of Eulimide and resembles that of 
Pyramidellide, but the shell is, in the recent species, usually 
more slim than Pyramidella, and without columellar folds, or 
with a single small fold. It differs from Eulima in being sculp- 
tured. $ 
Most of the recent species are of quite small size. 
TURBONILLA, Risso. 
Syn.—Chemnitzia, adOee:, 1839, not 1850. Pyrgiscus, Phil. 
Orthostelis, Arad. 
