234: THE CHICAGO ACADEMY OF SCIENCES. 



moides in general form and may be distinguished by the presence of 

 the heavy impressed spiral lines. 



Half-grown specimens with short spire have been identified as 

 umbilicata by many students and have been so reported from various 

 parts of the country. A study of Adams' specimen of umbilicata has 

 shown, however, that these authors were in error, Adams' specimens 

 being quite a different shell. (See umbilicata.) Caperata was at first 

 thought to range under stagnicola, but its wide, flat inner lip, and the 

 shape of the prostate, places it rather in typical Galba, with cubensis 

 and truncatula. 



Say's type of caperata is not in existence. A somewhat worn 

 specimen with long, scalar spire is preserved in the collection of the 

 Academy of Natural Sciences of Philadelphia (No. 58824), marked 

 as follows, in MS.: "Lymncea caperata Say. Illinois. N. H. Dis- 

 seminator, Vol. 2, p. 230. Ex. Auct." This specimen differs but 

 sl : ghtly from Binney's figure 87, being a trifle more scalariform. It 

 agrees well with Haldeman's figure 3 on plate 11 of his monograph. 

 Smiths oniana Lea is an absolute synonym of caperata, differing only 

 in size, in its shorter spire and in its darker color. Lea's types in the 

 Smithsonian Institution do not differ from caperata as found in Indiana 

 and Illinois. Specimens recently collected in the south branch of the 

 Platte River near Fort Morgan by H. W. Clatworthy (Ex. Mr. Junius 

 Henderson) are identical with Lea's types. Ferrissi Baker is simply 

 a markedly scalariform example of caperata. (Plate XXIX, figure 3.) 



Caperata has been kept in an aquarium in the writer's study for 

 many months at a time. While in confinement many specimens ate 

 holes in each others' shells for the lime needed to build their own shells. 

 An egg mass of this species was laid March 16, 1897. It contained 

 45 eggs, distinctly nucleated, and in a jelly-like mass measuring 11 

 by 2 mill. On March 18 a second egg mass was laid and on the 19th 

 three more masses. On the 22nd three individuals were seen in coitu, 

 each one endeavoring to play the active part. Of the five egg masses 

 laid each contained the following number of eggs : 42, 42, 35, 45, 28. 

 The eggs were spherical in shape and very distinctly nucleated. 



Galba holbollii ( (Beck) Moller). Plate XXIX, figure 4. 

 Limnaa (Limnophysa~) holbollii BECK, Index, p. Ill, 1838. (Nude name.) 

 Limnaa holbollii MORCH, Moll. Gron., p. 76, 1857. BINNEY, Check List, p. 

 12, 1860; L. & P.-W. Sh. N. A., II, p. 59, fig. 91, 1865. MORCH, Amer. Journ. 

 Sci., IV, p. 36, pi. 4, fig. 8, 1868. TRYON, Con. Hald. Mon., p. 101 (75), pi. 17, 

 fig. 11, 1872. Sows., Conch. Icon., XVIII, sp. 22, pi. 4, fig. 22, -1872. STEEN- 

 STRUP, Mai. Blatt, n. s. I, p. 17, 1879. WEST., Vega Exp., IV, pp. 167, 169, 170, 

 1885. 



