UROCOPTIDyE. ix 



off a few strands, which insert distally in the vagina. The 

 vas deferens then becomes involved in them, as in Brachy- 

 podclla chemnitziana ; and by gradual movement along the 

 v. d., these muscles finally reach the apex of the penis, and 

 assume the function of its normal retractor, which then de- 

 generates and is lost. 



The eggs of Eucalodium are elliptical, with white, hard 

 shell, rough to the touch, and showing crystalline facets 

 under a lens. They are comparatively large, that of E. de- 

 collatum gliiesbregliti measuring 11.2x7.2 mm. E. mexi- 

 canum was found by Crosse and Fischer to have a similar 

 egg, but that of E. walpoleanum (belonging to the subgeuus 

 Oligostylus) is smaller and narrower, 7x4 mm. Some species 

 of Bracliypodella (subgenera Apoma and Mychostoma) are 

 viviparous. 



The ALIMENTARY CANAL is much lengthened, and appar- 

 ently varies to a considerable extent in the various genera. 

 In the forms I have studied the long oesophagus coils close 

 to the axis of the shell as far as the stomach, which lies high 

 in the spire ; beyond the stomach there is a loop, after which 

 the hind-gut follows along the suture (see vol. xv, p. 2, Euca- 

 lodium; p. 69, Holospira; p. 108, Urocoptis}. The pharynx 

 or buccal mass is always short, as in the Helicidcc. 



The JAW is thin, and varies from nearly smooth (as in 

 some species of Holospira, vol. xv, pi. 27) to vertically striate 

 (Holospira}, or deeply, irregularly striate, almost plaited 

 (Anisospira, etc., xv, pi. 63), or with very wide, flat plaits 

 (Berendtia, xv, pi. 19, f. 45). In the subfamily Urocoptina 

 it is very thin, highly arched, and composed of many narrow, 

 slightly imbricating plaits, which converge so that there is a 

 triangular area of short plaits in the middle. A similar wide 

 range of structure has been noted in the jaw in the families 

 Helicidce (vol. ix, p. xii), and Bulimulida. 



The RADULA, in the unspecialized Mexican genera of Euca- 

 lodiina resembles that of the Helicidce or unspecialized Buli- 

 mulidcu, both in its general proportions, the nearly straight 

 transverse rows of teeth, and the form of the latter. In this 

 subfamily the central tooth is as wide as the laterals. It is 



