1899.] NATURAL SCIENCES OF PHILADELPHIA. 191 



other Belogonous genera, though peculiar in wanting a differentiated 

 receptacle and duct. 



In the genital system, therefore, P. viiorhyssa has no resem- 

 blance to Polygyra and its allies, Praticolella and Polygyrella ; and, 

 in fact, could not be included among the Protogonous Helices. 

 The genitalia are those of the Epijjhallogona or of Belogona 

 which have undergone degeneration of the dart sack and associated 

 mucous glands." The first of these groups includes the large, 

 heavy, dark-colored Helices of the West Indies and South Amer- 

 ica (Pleurodonte) , and various Oriental forms ( CamcBna, Planispira, 

 etc.), all quite unlike Ashmunella couchologically. The characters 

 of the lung and kidney cannot be adequately discussed owing to the 

 lack of published data of sufficient exactness, but the high value of 

 these organs in classification demonstrated by a mass of unpublished 

 data demands brief mention here. In Polygyra the kidney is very 

 long, usually over half the entire length of the lung cavity,* and is 

 band or ribbon-shaped, while Epiphragmophora has a short kidney, 

 hardly one-third the length of the lung cavity. In A. miorhyssa 

 the kidney is short, like that of Epiphragmophora, and quite 

 unlike the kidney of any Polygyra yet examined. 



The jaw and radula give no characters differentiating >.4s/i?rtune/Za 

 from Polygyra, Epiphragmophora or numerous other genera of 

 ground-living helices. The teeth are very similar to those of 

 Polygyra. 



In the shell we can find no characters whatever which are not 

 readily paralleled in Polygyra. Some of the Epiphragmophoras 

 of the islands off California and Lower California are somewhat 

 similar in shell characters. 



Upon the Avhole, it seems likely that Ashmunella is a member 

 of the Belogona Euadenia or Asiatico-American group of dart- 



*See under Metafrutickola, etc., in the "Guide to the Study of Helices." 

 American examples of partial degeneration of these appendages are Epiph rag- 

 mophora guadalupiana and the genus Glyptoitonia. See Proc. Acad. Nat. 

 Sci. Phila., 1898, p. 67. 



*The exceptions are P. septemvoUa and probably its immediate allies, 

 with very narrow whorls, in which the lung, in common with the whole 

 mantle, is excessively lengthened in harmony with the narrow cavity of the 

 shell, while the kidney and heart retain the form found in species with 

 normally proportioned shells. This exception is no argument against the 

 value of the form of the kidney as an index of affinity, but rather one in 

 its favor. 



