70 THE NAUTILUS. 
scribed of the genera Pleurotoma (sensu latissimo), Cerithiella, 
Amphirissoa (a new Rissoid genus with continuous, reflexed peri- 
stome), Basilissopis (a new genus resembling Basilissa, but not 
pearly, ete.), Eulima, Niso, Turbonilla, Turcicula, Cyclostrema, Coe- 
culina, Puncturella, Aemea, Aliceia (name preoccupied), Isomonia 
(new group of Anomiide), Chlamys, Amussium, Myrina, Area, Leda, 
Malletia, Cardium, Azinus, Diplodonta, Cuspidaria, Verticordia, 
Thracia and Poromya. A\l| the new formsare figured, but the pho- 
totypes are not so clear in detail as we could desire, being decidedly 
inferior to those illustrating “ Les Mollusques Marins du Roussil- 
lon,” for example. Otherwise the work seems well done in every 
respect. 
In treating the Scalide and the genus Mathilda obtained by the 
same expedition,? Mr. Dautzenberg has the able assistance of Mr. 
E. de Boury, well known for his studies on Scalide. Thirteen spe- 
cies are recorded, of which seven are new. 
BREEDING SrnistRAL Herices.—Arnold Lang, in Vierteljahr- 
schr. Naturf. Ges. Ziirich, XLI, 1896, Jubelband, p. 448, gives the 
results of two experiments to ascertain whether as a rule sinistral 
individuals of normally dextral snails produced sinistral or dextral 
young. The experiments were conducted two consecutive years, 
once with seven, another time with nine individuals of Helix poma- 
tia. They were completely isolated; and the result was only dex- 
tral young. No less than 241 young were obtained from the lot of 
seven. 
Edwin Grant Conklin, Professor of Comparative Embryology in 
the University of Pennsylvania, has published in the Journal of 
Morphology for April, 1897, an elaborate work on the Embryology 
of Crepidula, with especial reference to the “cleavage of the ovum, 
the formation of the germinal layers and definitive organs, and the 
axial relations of the ovum to the larval and adult axes.” The 
work is too extensive for abstract here, being, in fact, one of the 
most thoroughly worked out studies in “cell lineage” yet produced 
in America, and especially valuable for the attention given to the 
later stages with the object of tracing the individual blastomeres of 
the cleaving egg onward to the germ layers. The interesting obser- 
vations upon the natural history of Crepidula forming part of the 
prefatory portion of Prof. Conklin’s memoir, we hope to reprint 
later. 
2 Same volume. 
