48 AMERICAN JOURNAL 



II 



DESCRIPTION OF THE GENUS AEIOLIMAX, MORCH*. 



liY W. G. BINNEY. 

 Plate G, Figures 11, 12, 13. 



Body attenuated towards the posterior extremity, whicli is 

 carinated strongly. Surface with oblong tuberosities. Mantle 

 anterior bluntly truncated before and behind, minutely granu- 

 lated, free at the front and sides, attached posteriorly, con- 

 taining a testaceous rudiment. Longitudinal furrows along 

 the sides above the foot. Locomotive disk? Respiratory orifice 

 at the posterior third of the shell. Anal orifice? Orifice of 

 the generative organs — ? A caudal mucus pore. 



Testaceus rudiment hexagonal longer than wide, ends 

 pointed acutely, not spiral. 



Jaw arcuate, with numerous crowded anterior ribs, denticu- 

 lating; the concave margin. 



Lingual membrane, (of A. Cohtmhianvs,) very broad and 

 long, composed of about 120 rows of teeth, each row contain- 

 ing 113 teeth, 56-1-56. Central teeth, large, with a long 

 medean cusp. Side cusp obsolete ; lateral teeth bicuspid, the 

 inner cusp longer and more slender than the outer, and 

 becoming proportionally still more slender and lengthened as 

 the teeth are modified in passing off" laterally. 



This genus is founded on the large species inhabiting the 

 Pacific States, known as Limax ColuTnhianvs. It is readily 

 distinguished from Ar.on by its internal shelly plate, and the 

 position of the respiratory orifice; from Limax by its dentate 

 jaw. The only species of Gcomalacus yet known has an 

 internal plate, but its respiratory orifice is much more 

 anterior. 



The figures are used by permission of Prof Henry, in ad- 

 vance of the "Landand Fresh-waterShells of North America," 

 being prepared by the Smithsonian Institution. 



* Mandidulum costatum ; porus caudalis Arionis; corpus postice 

 carinatum ; orificium respiration in tertia parte postica clypei situm. 

 Testa interna hexaffonalis. — Morch. Malak, Blait. vi., 110. 



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