1878.] FROM JAPAN AND BORNEO. 497 



oblique thread-like lines of growth when viewed under a lens. The 

 descent of the body-whorl is very sudden and brief. The whorl, 

 owing to the expansion of the peritreme, has a constricted appear- 

 ance in that part. 



The umbilicus is a little more open than in H. congener, and 

 consequently more perspective. The coloration of this species is not 

 easily definable. The ground-colour is pale straw, the oblique raised 

 lirse being more opaque and yellower. The body-whorl below the 

 periphery is stained with brown, or looks as if it were scorched. 

 The colouring takes the form of a very broad interrupted transverse 

 band, or, in other words, of wide blotches or stripes. The latter are 

 sometimes continued upon the upper half of the whorl, and are also 

 here and there faiutly observable on the upper volutions. One 



Fig. 2. 



Helix (Camena) congenita. 



specimen has a narrow peripherial brown band. The body-whorl is 

 stained with brown outside the tip ; and this, owing to the thinness 

 of the shell, produces a brownish labrum, which in some places, 

 particularly at the extreme edge and in the columellar region, is 

 somewhat whitish. It is rather widely expanded at the base and 

 columella, and is a trifle reflexed everywhere. The aperture is very 

 transverse, in fact almost horizontal ; it is of a livid white colour 

 within, exhibiting the brown marking of the exterior. 



Subgen. Myxostoma, Troschel. 



Testa plus minusve discoidea, late umbilicata ; apertura circularis ; 



peristoma duplex, margine interiore superne plerumque leviter 



sinuato, externa supra sinum alatim expanso. Operculum corneum, 



crassum, in/erne paulo concavum, in medio nucleo prominulo, extus 



marginibus anfractuum lamellosis. 



This section of Cyclophorus agrees with Pterocyclos in the form 



of the shell and its peristome, but differs in having a thick horny 



operculum, with the margins of the whorls lamellated exteriorly, 



that of Pterocyclos being calcareous and spirally laminated. 



Cyclophorus (Myxostoma) bathyrhaphe. 



Testa discoidea, apertissime umbilicata, spira parum elevata, sub 

 epidermide luteo-olivacea sordide vel caruleo-albida ,• anfr. 5|, 

 rotundaii, sutura valde canaliculata sejuncti, ultimus sat magnus 



