1911.] NATURAL SCIENCES OF PHILADELPHIA. 473 



once recognized by Mr. Ferriss and myself as unlike any Omphalina 

 we had seen, on account of the black lines of the lung showing 

 through the shell. 



As usual in this genus, it lives on moist, well-shaded hillsides, 

 buried in the leaf-covered humus up to the apex, which alone is 

 exposed. 



The external characters of foot and body are substantially as in 

 0. friabilis from San Marcos, Texas, except that the last half of the 

 last whorl, as seen through the shell in life, shows a few irregular, 

 sharply defined black lines on a pale, or in life cream-white ground. 



The pallial tract when opened (fig. 1 A) shows a short subtriangular 

 brown kidney, the ureter projecting well forward from its apex. 

 The secondary ureter is closed throughout. The pulmonary vein 

 branches somewhat freely near its anterior end, and there are two 

 slender, weak branches of the pericardial vein. All of these veins 

 are colorless, like the pale wall of the lung. Most of the branches of 

 the vena cava are intensely black and show on the outside as black 

 lines. This marking renders the subspecies easy to recognize in 

 the field or when handling alcoholic specimens. 



The genital system (PL XXXVII, fig. 3) is practically identical 

 with that of 0. friabilis from San Marcos, Tex., but differs in the 

 following points: the base of the vagina is not swollen, the penis 

 is more slender and the muscle controlling the epiphallus is inserted 

 at the distal third of the latter instead of near its end. 



The epiphallus is inserted about midway on the penis, whereas 

 in 0. cwprea it inserts near the distal end. The organs of the indi- 

 vidual drawn measure: 



Length of penis 7.5 mm. 



" epiphallus 14 



" vagina 6.3 " 



" " spermatheca and duct 13 " 



Two radulae examined agree essentially with 0. cwprea. Formula 

 of teeth about 54, 6, 1,6, 54. 

 Two shells measure: 



Alt. 15.0, diam. 25 mm. 



" 13.3, " 22 " 

 The jaw is yellow, with truncate ends, the median projection 



either low or strong. 

 31 



