THE NAUTILUS. 35 



and new species figured. Cionella lubrica and Pyramidula striyosn 

 are among the northern species occurring in the Boundary region. 

 The discussion of the Boundary fauna is followed by an extended 

 treatment of the Lower Califbrnian Bulimuli,ii\ which a number of 

 obscure matters are righted. In conclusion is given a list of marine 

 mollusks from the termination of the international boundary and 

 from San.Clemente Island. 



Evidence is adduced indicating that within comparatively recent 

 geologic time, probably Post-Pliocene, Mexico has been almost in- 

 sulated from the Continent north of it. 



The Journal de Conchyliologie for April, 1896 (issued about 

 April 7, 1897), contains an important article on Pleurobranclms and 

 related genera, by Prof. A. Vayssiere, of Marseilles. 



Dr. R. Ellsworth Call has added a valuable paper to the scant 

 literature of American cave faunas in his Notes on the Flora and 

 Fauna of Mammoth Cave, Ky. (American Naturalist, May, 1897). 

 The only mollusk found by him in the cave is a Carychium, consid- 

 erably like C. exiguum, which he describes as C. stygium. About 

 150 examples were collected in " Mammoth Dome," on the wet sur- 

 faces of old bridge timbers, which have been lying undisturbed for 

 forty or fifty years. 



Dr. Heiurich Sim roth gives a preliminary communication upon 

 Russian slugs, 1 based upon the study of materials in the Zoological 

 Museum of the Imperial Academy and the Senckenberg Museum 

 at Frankfurt. The Caucasus Mountain region is the district of 

 greatest peculiarity, having a number of special types. Simroth 

 truly says that for the satisfactory working out of the species and 

 their inter-relationships, the investigation of the genitalia and intes- 

 tinal tract suffice ; but for the understanding of the genera and 

 their phylogeny, the other organs, especially the heart, pallial re- 

 gion, kidney and lung must be examined, a condition very rarely 

 fulfilled. The Testacellidce and Arionidce are briefly commented on, 

 and the following genera of Limacidce noted : Agriolimax, Para- 

 Umax, Lytopelta, Gigantolimax, Metalimax, Monochroma, Parma- 

 cella. Metalimax and Monochroma are new, the former near Para- 

 Umax, but differing in the male genitalia; the latter is near Limax, 

 but the eye-retractor does not pass between branches of geuitalia, 



^Vnnuaire du Mus. Zool. de 1'Acad. Imp. des Sci. de St. Petersburg, 1896. 



