1882.] American Work on Recent Mollusca in 1SS1. S77 



of text and sixteen plates, figuring ninety-five species of Califor- 

 nian shells, which are described in a conversational way in the 

 text. Little is said of systematic classification, and wisely so. 

 As it is, the book is well suited to assist the young to a knowledge 

 of the names and more obvious characters of the shells they are 

 likely to find on the shore, and to interest them in the general 

 subject. The figures are very characteristic and in many cases 

 unusually good. 



The draughtsman with some instruction would evidently do 

 better work than is common. But we trust that, should Mr. 

 Keep issue a larger work, as it has been hinted he would do, and 

 his present draughtsman should assist, the latter will examine 

 some standard works (like Adams' Genera, for instance) and ob- 

 serve that the axis of the spire should be kept at right angles to 

 the line of sight, by which the foreshortening and distortion 

 which spoil some of his figures of Gastropods {e. g. PL VI, Figs. 

 4, 6, 7; PI. vii, Figs. 1, 2) will be entirely avoided. This criti- 

 cism excepted, we cordially welcome the little book, which can 

 be obtained of the a'uthor himself for the price of one dollar, by 

 those who wish to encourage such enterprise. 



Anatomy, Physiology and Development — -The most important 

 work in this department which has appeared during the past year 

 is that on the "Maturation, fecundation and segmentation of Umax 

 campestris Binney," by E. L. Mark (Bull. Mus. Comp. Z06L, VI, 

 Nc, 12, 8vo, pp. 173-625, PI. i-v, Oct., 1881). This paper, 

 according to a note by the author, was prepared early in 1879, 

 though its publication has been long delayed, and has already 

 been noticed in the Naturalist. Its length and character forbid 

 any attempt at analyzing it in detail here. This is the less to be 

 regretted, since those who are in a position to profit by the obser- 

 vations and deductions therein set forth, will by no means fail to 

 inform themselves from the original, while any attempt to con- 

 dense for others the deductions from such investigations, could 

 hardly result in an adequate representation of the author's posi- 

 tion. The work, in execution and presentation, is creditable to 

 American science and to the author, and will form, we hope, 

 merely a beginning of his achievements in this direction. 



A reference was made in the record for 1880 (p. 709) to Profes- 

 sor Alpheus Hyatt's lecture on the " Transformation of Planorbis 

 at Steinheim." In the Proceedings of the Am. Assoc. Adv. Sci- 



