134 XENOTHAUMA. 



The variegated color-pattern differs from that of A. multicolor in 

 detail. The sculpture shows A. turnix to be related to A. hybridus, 

 a species with carinate base. The specimen described was received 

 from Dr. v. Ihering. Gould's type measured : length 2|, diam. 

 lrVxi 9 o, aperture 1 T % inches, (about 55 mill, long, 27^ wide, with the 

 aperture 32J mill. long). Gould describes the lip as strongly revo- 

 lute and roseate. 



A specimen in the American Museum of Natural History, Central 

 Park, New York (No. 5148a), measures: length 50, diam. 27-J, 

 longest axis of aperture 32J mill. The lip is rather broadly reflexed 

 and white. Cuticle yellow, showing the usual brown and white 

 markings (fig. 53). It is from the Organ Mts. 



Genus XENOTHAUMA Fulton. 1896. 



FULTON, Ann. and Mag. N. H. (vi), xviii, p. 102 (July, 1896). 

 CROSSE, Journ. de Conchyl. 1898, p. 205. 



Shell broadly umbilicate, depressed and keeled, heliciform, chalky, 

 opaque and spirally striate, the nepionic whorl projecting, sculptured 

 with much-dislocated vermiculate wrinkles; last whorl deeply de- 

 scending, free in front, the aperture subhorizontal with continuous, 

 broadly flaring peristome, reflexed below. 



An extraordinary form, the position of which can be settled only 

 by investigation of the soft anatomy. Mr. Fulton thought it might 

 be near Epiphragmophora. Crosse also considered it a " Helix," 

 which he would group with H. reentsi Phil. (Platybostryx). In my 

 opinion Xenothauma is Bulimulid, and has been modified from the 

 Peruvian group of Scutalus of which B. baroni, B. steerei, etc., are 

 typical members. It is parallel with, but not related to, Platybostryx, 

 which has diverged from the Chilian Lissoacme type of Bulimulus. 



X. BARONI (Fulton). PI. 24, figs. 6, 7, 8, 9, 10. 



Shell depressed, lens-shaped, orbicular in circumference, acutely 

 carinate, with a wide, conic umbilicus ; calcareous, lustreless, rusty 

 brown. Sculpture of numerous narrow and rather acute spiral cords 

 running over rough, irregular growth-striae, the cords larger beneath. 

 Whorls 4^, the first one projecting, the earlier If forming a wrinkled 

 nepionic shell ; subsequent whorls but slightly convex, the last 

 pinched out in a compressed, thin peripheral keel, deeply descending 

 and becoming free in front, convex beneath, carinate around the 



