360 On the genus Pompholyx and its Allies, ' 



Several specimens should always be examined when possible, 

 as a certain range of variation is possible, and in this way a bet- 

 ter general idea of the ribbon is obtained. 



Much of the anatomy may be made out by crushing the fresh 

 animal gradually under the cover of the live-box. 



The viscera are liable to be misplaced by this process, and 

 Other specimens should be dissected with needles or fine scissors. 



For works of reference, Leidy on the anatomy of the Terr. 

 Gasteropoda of the U.S. (in A. Binney's Mon. Hel.) maybe 

 consulted for the land species; — while Bronn, and Moquin 

 Tandou are almost the only ones who have given much in- 

 formation in regard to the anatomy of the fresh-water forms. 

 Cuvier, Vogt, and Baudelot have added much information in 

 detached papers in regard to a few species. 



While authors may disagree as to the value of the lingual 

 dentition as a basis for classification, yet all must admit that 

 every reliable addition to our knowledge of the subject is of 

 great importance, and the details of the anatomy much more so. 



Huxley has recently classified the air-breathing Mollusca by 

 tiie flexure of the intestine. While his ijeneralizations have a 

 very Blender ba>is of fact, and are rejected by almost every ma- 

 laoologist, yet. until dissections on a more extended scale have 

 been made, no one has the right to consider them as utterly ab- 

 surd. nor yet to accept them as proven. 



REFERENCES TO THE PLATE. 



Fi<j. 1. - Dissection of Pompholyx var. soUda, Dall ; showing 

 the digestive and female generative system, with the organs 

 about the month, as if transparent. 



a, Ami-. It. Buccal plate, c, Crop, d, Auxiliary mucus 



gland, e, Outlet of stomach into intestine, f, Male aperture. 

 I, descending intestine, k, Stomach, m, Buccal mass, n, Mus- 

 cular band of stomach, o, (Esophagus, ov, Oviduct, p, Pul- 

 monary cavity, r, Lingual ribbon, re. Rectum, s. Organ of 

 smell surrounded by the salivary gland, t. Ovary, u, Uterus. 

 \. [aver. /.. Edges of mantle laid back. 



