402 A MANUAL OF AMERICAN LAND SHELLS. 



Counties, Kentucky. Very common in Central xVlabama, wliere im- 

 mense beds of semi-fossilized shells are found several feet below the 

 surface. 



This species, when found in IS^orthern Alabama, is about three- 

 fourths of an inch in length, is (juite thin, almost transparent, with a 

 thin i)eristome. In more southern localities its size is greater, its shell 

 thicker, its coloring richer, and within the aperture the peritreme is 

 margined with a broad white callus. Under such circumstances it 

 bears considerable resemblance to B. nlternatns, but the interior of the 

 aperture never has the dark coloring of that species nor is the colu- 

 mella furnished with the tooth-like fold. It is especially in Texas 

 that it is found in such perfection. I have no doubt that the specimens 

 figured on Plate LI, a, of the Terrestrial Mollusks came from that 

 State. 



It is this last-described form of the species which has been called 

 Bulimus lactarius. I have seen no authentic specimen, but from Pfeif- 

 fer's description (see Terr. Moll., IV, 128), and his reference to all but 

 the lower figure of Plate LI, a (Mon,, IV, 476), there remains no doubt 

 of the identity of the two. 



The variation in the globoseness of the whorls, and consequent 

 outline of the shell, may be judged from the following measurements 

 of two specimens : Diameter, 18""" ; length, 25""". Diameter, 7"'" ; length, 

 19"*™. 



Of Bulimus liquabilis and confinis 1 have given the original descrip- 

 tion and a facsimile of the original figures in the fourth volume of the 

 Terrestrial Mollusks. 



The jaw of BuUmiilus dealhatus is narrow, strongly arched, with dis- 

 tant, very delicate anterior ribs, denticulating the concave margin. 

 (See above. Fig. 430.) 



The lingual membrane consists of. 94 rows of 25-1-25 teeth. (See 

 above, p. 395.) 



The anatomy is figured by Leidy (/. c). The penis sac is very long; 

 its upper portion is narrow and very tortuous and tiagellate in appear- 

 ance, although the true flagellum, or the free portion of the summit 

 of the penis beyond the insertion of the retractor muscle, is very short. 

 The lower third of the penis is dilated, and presents an annular con- 

 striction ; at its base it is enveloped by a short prepuce. The vas def- 

 erens follows the course of the penis nearly to its summit. The gen- 

 ital bladder is oval, its duct as long as the oviduct. 



