AMPHIDROMUS. 127 



above, yellow and smooth below. Pattersonia. Fig. 85 is clear 

 greenish-yellow with a single dark belt; sculpture faint. Cataract 

 Hill. Fig. 92 is a very long shell from Port Davey, on the extreme 

 southwest of the island (Tenison-Woods). Figs. 89, 93 are extreme 

 forms from Ringarooma (Tenison-Woods). 



It is extremely probable that a number of distinguishable local 

 races exist, but they should be studied by some one familiar with the 

 local conditions, and with ample geographic series. 



Genus AMPHIDROMUS Albers, 1850. 



Amphidromus ALBERS, Die Hel. 1850, p. 138 (in part). MAR- 

 TENS in Die Hel. 1860, p. 184, type B. perversus Linn.; Ostas. ZooL, 

 Landschn., p. 332. SEMPER, Reisen, p. 146. FULTON, Ann. and 

 Mag. of Nat. Hist. (6), xvii, pp. 66-94. 



Shell of moderate size, dextral or sinistial, long-ovate, with 6-8 

 moderately convex whorls ; smooth (rarely ribbed) and light or 

 bright-colored, yellow predominating, often with green or brown 

 streaks, flames or bands. Apical whorls smooth or obsoletely pitted. 

 Aperture somewhat oblique, ovate, not contracted by teeth or folds; 

 peristome more or less thickened, expanded or reflexed, the colu- 

 mellar margin reflexed, with a very weak fold or none. 



Jaw thin and weak, with flat ribs crenulating the edges. Radula 

 with broadly V-shaped rows, the teeth of "arboreal" type, with the 

 side cusps brought near the median cusp, all the cusps broad ; out- 

 wardly the side cusps are split. Kidney extremely long and narrow, 

 with reflexed ureter and closed secondary ureter. Genitalia of typi- 

 cally epiphallogonous structure; receptaculum seminis on a long, 

 simple duct; penis short, with the retractor muscle inserted low, and 

 ending in a flagellum and the vas deferens. Nervous and retractor 

 systems Helicine. 



Type Helix perversa L. Distribution, Sylhet Hills and Indo- 

 China to Timor, east to Mindanao and possibly the Moluccas. 



Without ample illustration the internal anatomy cannot be fully 

 discussed ; but from the data supplied by Semper, Wiegmann and 

 Jacobi, it is clear to me that the genus does not belong to the Buli- 

 mulida but to that group of Helicidce called Ephiphallogona, of which 

 the genera Chloritis, Obba, Planispira and Papuina are leading mem- 

 bers. The exact inter-relationships of the genera of this group require 

 further elucidation. We know that Planispira, Chloritis and Thersites 



