334 Lingual Dentition and Anatomy of 



in JSfewcomhia and Laminella is simpl}^ bidentate or triden- 

 tate. Tills peculiar marginal tootli reminds one forcildy of 

 that figured for Partula by Heynemann (Mai. Blatt. 1869), 

 though the apex in his figure is not reflected as in Lepta- 

 cJiatina. 



Thus it appears that three groups are indicated by the 

 forms of lingual dentition in the genus Achatinella. 



a. Partidina, Achatinella s. str. 



b. NeiDcombia, Laminella. 



c. Leptachatina. 



As regards the subgenera not represented among Mr. 

 Gulick's specimens, judging from the shell alone, it would 

 appear that Bulimella and Apex belong to the group «, while 

 Labiella will prove to belong rather to b or c than to a. 



In the subjoined remarks on the anatomy of the geuus it 

 will be shown that there is another peculiar character, the 

 division of the ovary (albumen gland of Moquin-Tandon) 

 into long, wav}'-, delicate, thread-like caeca. No doubt this 

 is a generic character, so constant was. it in all of Mr. Gu- 

 lick's specimens examined, both of sections a and b indicated 

 above. 



In this connection it is interesting to state that Mr. Gulick, 

 in his paper "On the Variation of Species as related to their 

 Geographical Distribution, illustrated by the Achatinella3," 

 (Nature, July 18, 1872), states as follows: "The family is 

 divided into two natural groups of genera. The first group 

 consists of seven genera : Achatinella, Bidi7nella, Helicter- 

 ella, Partulina, JVewcombia, Laminella and Auriculella. 

 These are all arboreal in their habits. In form they are 

 sinistral, or both dextral and sinistral. The second group 

 consists of three genera : Amastra, Leptachatina and Care- 

 lia.* With but few exceptions, the species of Amastra and 

 Leptachatina live on the ground and are of dextral form." 



This division, apparently based more especially on the 

 sinistral or dextral characters of the shells, and arboreal or 



* Carelia, H. and A. Ad., a subgenus of Achatina, teste von Martens. 



