782 SCIENTIFIC KECORD FOR 1885. 



amiuation by the same gentleman. The results have appeared in a new 

 volume, entitled " A Manual of American Land Shells," which consti- 

 tutes "No. 28" of the Bulletin of the U. S. National Museum. 



The treatment is essentially the same as that in Mr. Binney's previ- 

 ous publications, but instead of the species being arranged in a regular 

 systematic order they are distributed geographically under several cat- 

 egories : {a) those " universally distributed ; " {b) those of the " Pacific 

 province ; " (c) those of the " central province ; " {d) species of the 

 '^ eastern province," and the "northern region" thereof; {e) species of 

 the "eastern province" and the "interior region;" (/) species of the 

 "eastern province" and the "southern region," and (r/) those "locally 

 introduced." 



After a brief introduction on (1) the " habits and properties," (2) 

 " geographical distribution," (3) the " generative organs," (4) the "jaws 

 and lingual dentition," and (5) the " classification," the author enters 

 upon the description of the species under the geographical categories 

 enumerated. 



With Dr. Fischer, he divides the Geophilous Pulmonates (to which 

 the volume is restricted) into two groups (1) the Monotremata, dis- 

 tinguished by having common or contiguous external male and female 

 orifices, including almost all of the species, and (2) the Ditremata, em- 

 bracing those forms in which the external male and female orifices are 

 widely separated. Of the latter group only two species of the family 

 VeroniceUida? and two of the Onchidiidse have been observed within 

 the limits mentioned. 



The Monotremata are divided into eleven families. These families do 

 not always appear to be very natural and sometimes discordant forms 

 have been combined in one, and sometimes forms for which no differ- 

 ential characters have been noticed have been referred to distinct fami- 

 lies. 



A r4sum6 of those families to which distinctive characters can be 

 given seems appropriate in this connection. 



I. The Glandinidse include those forms which are entirely destitute of 

 a jaw, and whose teeth are of only one kind, all being elongated, narrow, 

 and aculeate, while the mantle is submedian or postmedian and entirely 

 included in the shell, which itself is elongated or turreted. Of this 

 family five are enumerated as species of the genus Glandiua. These, in 

 Mr. Binney's plan, belong to the family Testacellidne. 



II. The Selenitid^ constitute a group, recently recognized by Dr. 

 Fletcher, of which the jaw is ribless, the teeth are of nearly the same 

 character as those of the Glandinidte and are aculeate, the median one 

 being either suppressed or very small, and the mantle is submedian or 

 posterior and included within the shell, which latter is spiral and helici- 

 form. The species of this group are referred by Mr. Biuney to the ge- 

 nus Macroyclis, and six are recognized as inhabitants of the North 

 American fauna. 



