HELIX-CAM^ENA. 209 



A species excessively variable in size and coloration. The follow- 

 ing forms are doubtless nothing more than stages in a continuous 

 series of modifications. See on this matter, Dohrn, Nachrichtsbl. 

 D. M. Ges., 1889, p. 61. 



The typical monochroa differs from the form called palawanica in 

 nothing but the color of the lip, which is whitish, shading into deep 

 brown on the outer edge. It is said to be from the island of Tablas, 

 Philippines, and one of the specimens before me being labelled 

 " Tablas " I have no especial reason for doubting it. 



The palawanica of Pfeiffer (pi. 22, figs. 58-62) is large, variable in 

 degree of depression, and the color varies from (1) light yellowish 

 all over, with narrow brown bands at suture and periphery, the in- 

 side of the umbilicus brown, to (2) deep purplish brown (the spire 

 light brown) encircled at periphery by a blackish line. See also 

 pi. 42, fig. 19 for color-varieties. The lip is entirely purplish-brown. 

 It is before me from Palawan and north-eastern Borneo. 



The H. saulice Pfr. (pi. 42, fig. 23) is small, solid, light brown, en- 

 circled by a single subperipheral dark zone. Alt. 20, greater diam. 

 32, lesser 27 mill. A specimen before me differs from the typical 

 saulice in having a light peristome, edged with brown. It is figured 

 on pi. 42, fig. 22. 



If. lagunce of Hidalgo (pi. 26, fig. 9) is an elevated form ap- 

 proaching somewhat to trailli in outline and system of coloration. 

 The four brown bands, says Hidalgo, are disposed in the following 

 manner : two very narrow ones, one at the suture, the other at the 

 periphery ; the two others are situated at equal distances from the 

 peripheral zone, above and below it. The upper of these is wide r 

 and continues up the spire on the middle part of the whorls, gradu- 

 ally fading out ; the lower band is wider still and of a darker hue ; 

 it enters the aperture, its upper margin touching the superior termi- 

 nation of the right lip. It is from Luzon, but the precise locality is 

 not known. 



H. dorice Dohrn seems to be the dark reddish or chestnut-brown 

 form, of which many examples are before me. It may be noted 

 that the dark-colored specimens from northern Borneo are larger, 

 solider, and have thicker peristome than those from Palawan. 



H. PALUMBA Souverbie. PI. 27, figs. 18, 19; pi. 41, figs. 12, 13, 

 14, 15. 



Shell half covered umbilicate, depressed-globose, thin and light, 

 of a light brownish color, encircled by a pure white zone at the 

 14 



