152 AMPHIDROMUS, GROUP IV. 



The outline of this species is rather straighlly conical, and the 

 form less obese than in typical A. perversus, the aperture being 

 smaller. The color-patterns differ from those of perversus. 



CELEBES. Near Maros, in southern Celebes, Dr. von Martens 

 collected three color-forms of interrupts s : the typical, tigs. 55, 56 

 (also called infrapictus} ; var. striyosus, figs. 57, 58 ; and var. in- 

 fraviridis, figs. 59-65. The species occurs in manifold contour and 

 color-varieties, if not all combinations of both. Among the Maros 

 examples there are two numerically prevalent forms : moderately 

 large infraviridis of conic-ovate shape and rather thick lip, fig. 65, 

 and small " infrap ictus " of rather elongate shape with strongly 

 thickened lip, fig. 55. The intermediate forms, as well as the quite 

 slender and the entirely streaked, occur only in occasional individuals, 

 though sufficient to prove the connection of the series. This is also 

 demonstrated by comparison of the Javan examples, of which there 

 were many connecting the varieties, and showing that a division is 

 no more to be based upon locality than upon color and contour 

 (Ostas. Zool. Landschn., p. 345). 



The above data prove that the color-forms represented on pi. 52 

 have no truly varietal status, but are simply individual variations 

 comparable to the well known band variations of Helix nemoralis. 

 Miiller's type was an individual of what Prof, von Martens has called 

 var. infrapictus. About three-fourths of the specimens examined by 

 von Martens are dextral. 



Of 10 greenish-yellow specimens before me, half are dextral. 

 Most of them have a white or bluish varix, and some a white basal 

 patch. The lip is white throughout. None of them are perceptibly 

 greener below than above, but otherwise they agree with Prof. v. 

 Martens' color-var. infraviridis. 



Figs. 41, 42 of pi. 50 represent a peculiar form from coll. John 

 Ford, locality unknown, remarkable for its very elongate shape. 

 There are 7 whorls, the last with a gray-white or greenish varix. 

 The lip is recurved, enveloping and adnate, white throughout. 

 Color sulphur-yellow, paler above. Length 50, diam. 21, aperture 

 23 mill. 



P. and F. Sarasin found interruptus very variable in form at 

 Makassar, 17 dextral, 10 sinistral specimens. The ground color is 

 sometimes very light, sometimes dark yellow, and rarely almost 

 white. Markings typical (" infrapictus ") or of the sultanus pattern, 



