46 GUDE : ON GORILLA ERRONELLA. 



first (upper) shortest ; the second longest, united to the sinuous fold at the 

 aperture, free posteriorly ; the third — near the lower suture — slowly ascending 

 posteriorly. Palatal folds four: the first (uppei) shortest, slightly curved, 

 descending posteriorly ; the second longest, the anterior half ascending, the 

 posterior half almost horizontal ; the third, a little longer than the first, 

 scarcely curved, descending very obliquely posteriorly ; the fourth nearly as 

 long as the second, curved parallel with, and near to, the lower suture, and 

 reaching nearly to the aperture. 



Major diam. 16—18, minor 12.5; alt. 5.5 millirii. 



Hah. — Ceylon. Type in Col. Beddome's collection. 



From Corilla I'rronca, Alb., its nearest ally, C. crroni'Ua differs in its more 

 regular contour and its smaller size. The riblets are more pronounced and 

 more regular and do not anastomose, while the incised spiral lines on the 

 lower surface, so conspicuous a feature in C. erronea and many of its allies 

 are usually lacking. In the armature there are considerable differences : the 

 the second parietal fold, which in C. fi-ronoa is united posteriorly to the first, 

 is here (juite free posteriorly. The palatal folds are generally shorter and 

 much nearer the peristome, being all visible from the aperture ; while the 

 third fold, which in C frnmea is very short and nearly horizontal, is here 

 longer and obliquely descending. Figs, i —3 show the shell in three different 

 positions, while a diagrammatic view of the armature is given in figs. 4 and 5, 

 the former showing the parietal folds and the latter exhibiting the palatal folds 

 as they appear within on the outer wall. A number of immature shells show 

 the usual five palatal folds, the first four very oblique, the fifth small and 

 horizontal, but no parietal barriers, which do not appear to be formed until 

 the shell reaches maturity. 



