BDELLOID ROTIFERA OP SOUTH AFRICA. 79 



borders of the spurs, but usually tbe wide interspace curves just 

 enough to appear convex. 



The corona is bold, with a sulcus equal to four-fifths of the 

 disc, and the relative proportions of the corona, collar and neck 

 are 11, 10, 8 J. The rounded upper lip has a gentle depression in 

 the front margin, and just covers the bridge of the sulcus when 

 the animal is horizontal. There is a small fleshy tooth in the 

 sulcus, generally hidden, and two membranes come down from the 

 wheels to near the middle of the sulcus bridge. There is a distinct 

 lip flap at the collar. 



The only Bdelloid at all near to this is C. as ferula Murray (8). 

 In general appearance and in some details they are very similar. 

 M. petulans, however, has a distinctly different type of spurs ; 

 has not got an exceptionally short rostrum ; has not the sharp 

 points on the upper lip, nor any peculiar shape of the first trunk 

 segment. It has a visible lamella, and the teeth never were 

 found to vary in number from three ; nor do the jaws show any 

 constriction. The most essential difference, however, is in the 

 character of the stomach. Murray had evidently paid particular 

 attention to the width of the lumen, as shown in his descriptions 

 of C. armillata, C. lepida and C. microcornis (7, 9). Having 

 thought it worth while to note these not very greatly enlarged 

 instances, he was not likely to have overlooked such a departure 

 from the common, had it existed in C. asperula. With regard to 

 C. asferula he neither mentions nor shows in his figure a wide 

 lumen ; besides, he had previously seen my sketch of M. petulans, 

 and would have kept an outlook for this distinctive feature. 



Habitat. — Tree and rock moss. Widely spread and abundant 

 at times. Grahamstown ; Uitenhage district at Bulk River, 

 Springfield, Van Staaden's pass and Draaifontein farm. 



Macrotrachela cuthberti sp. nov. 



PL 6, figs. 15-156. 



Specific Characters. — Of moderate size, and rather under 

 medium stoutness. Antenna very short, equal to one-fourth 

 neck width. Jaws small, square with three strong teeth. Con- 

 tractile vesicle large. Foot short, of apparently three segments. 

 Spurs small, sharp and scarcely divergent. Corona just visibly 



