13.0 AMPHIDROMUS. 



agreeing with those of Fulton. If the present groups are more 

 natural than his, it must be due to my having his work as a basis. 



I. AMPHIDROME DIVISION. 



Shell rather stout in figure, either dextral or sinistral, usually 

 solid, and with periodical color-stripes or " varices." 



Species of this division do not invade the island chain lying east of 

 Java, but extend east to Celebes and Mindanao, and north into 

 Anam and Burma. Species of the Second Division extend further 

 north and southeast, but do not reach so far into the Philippines. 



Key to Groups. 



a. Peristome white or nearly so. 



b. Surface costulate or strongly striate. 

 c. Form stout, compact; Java. 



Group of A. javam'cus, No. II. 

 c 1 . Form slender, diam. less than half the alt. Celebes. 



Group of A. beccarii, No. HI. 



b ] . Surface smooth or nearly so (rarely with spiral welts, or 

 a projecting varix). 



c. Umbilicate, large, early whorls dark-margined. Min- 

 danao, Leyte. Group of A. maculiferus, No. I. 

 c 1 . Imperforate or rimate, uniform yellow or white, or 

 variously marked. 



d. Plain, streaked or striped species of the Philip- 

 pines, Borneo, Celebes and Java. 



Group of A. perversus, No. IV. 



d l . Similar or rarely banded species from north of 

 Sunda Strait, Group of A. aureus, No. V. 



d 1 . Spirally zoned species. 



Group of A. janus, No. VI. 

 a 1 . Peristome colored, usually purple or rose. 



Group of A. scJiomburgki, No. VII. 



I. Group of A. maculiferus. 

 A. MACULIFERUS (Sowerby). PI. 49, figs. 19, 20, 21. 



Shell generally sinistral, narrowly umbilicate, oblong-conic, mod- 

 erately solid, glossy, variable in color, but typically grayish-brown, 

 shading to white just below the suture, irregularly streaked with dull 





