MANUAL OF THE MOLLUSCA. 
ScALENOSTOMA, Deshayes, 1863. 
Type, 8. carinatum, Isle of Bourbon. 
Shell in form allied to Pyramidella and WNiso, turriculated, 
white, imperforate; columella not plicated; opening subtri- 
angular, slightly bent in the direction of its length; margin 
simple, notched near the suture. ‘ 
CHEMNITZIA. Sub-genera :—Dunkeria, P. Carpenter (dedi- 
cated to Professor W. Dunker). Aperture as in Chemnitzia, 
but the whorls rounded as in Aclis; whorls cancellated. 
Distribution, 7 species. Mazatlan, Japan. 
Pseudomelania, Pictet and Campiche, 1864. 
Htymology, pseudo, false, and Melania, a generic name. 
Shell turriculated, spire acute, test thick, imperforate, 
without ornamentation. Aperture oval, rounded in front, more 
er less angulated behind; columella thick, conforming to the 
general curvature of the aperture; lip simple. 
Distribution. Trias—Chalk. Europe, South Africa. The 
cretaceous species are 14 in number. 
Kuuima. Sub-genus :—Leiostraca, H. and A. Adams (Balcis, 
Leach). ih 
Shell with a slight varix on each side of the spire. 
Distribution, 8 species. Mazatlan, Taboga. 
AcicuLiInA, Deshayes, 1864. 
Shell small, aciculated; apex laterally inclined; whorls 
numerous, conyex, smooth; aperture entire, small, subqua- 
drangular; columella straight, narrow, cylindrical, and simple. 
Distribution, 6 species. Hocene. Paris basin. 
MATHILDA, Semper, 1865. 
Shell turriculated, apex revolute, abruptly turned from left to 
right ; whorls in the typical species transversely cingulated 
and reticulated, longitudinally striated; aperture entire, subro- 
tund, base sometimes subeffuse; lip acute; columella smooth, 
not plicated. 
Distribution. The type Turritella quadricarinatus, Brocchi, 
is living in the Mediterranean, and is fossil in the Crag of 
Anvers, and at Bologna. 
Fossil, 13 species. Hocene—. Europe, United States. 
SOLENISCUS, Meek and Worthen, 1860. 
Etymology, soleniskos, a little channel or gutter. 
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