124 DESCRIPTIONS OF EARTHWORMS. 



colored ridge in the middle of each segment; in the an- 

 terior segments they are situated on the ventral side of 

 the body, however in the posterior segments the dorsal 

 pair of them is placed more laterally. The clitellum is very 

 distinct, extending from segment (13) 14 to (19) 20; it 

 shows at the ventral side a deep, rectangular groove over 

 its total length. The male generative apertures are situa- 

 ted in this depressed area , upon two pairs of papillae , in 

 the 17th and 19th ring. The copulatory pouches open be- 

 tween the 7th and 8th, the 8th and 9th segment, in front 

 of the ventral pairs of setae ; in the vicinity of the open- 

 ings there is a glandular , not well-defined area upon the 

 ventral side of segment 7 , 8 and 9. 



The penial setae present a very singular appearance , 

 quite different from that of the two other Liberian Acan- 

 thodrilus-8-pecies ^). The length of these bristles is about 

 3 m.m. Their distal extremity (fig. 3) is largely dilated and 

 is furnished with a structure , resembling somewhat a cap ; 

 the one side (we may name it the dorsal half) of this cap 

 is convex, smooth, bearing about 17 short, strong, hook- 

 shaped spines and presents along its inferior edge a pro- 

 minent brim, which is slightly folded and furnished with 

 some small teeth. The opposite part (the ventral half) of 

 the cap is divided by a ridge-shaped elevation in two halfs, 

 which are a little concave and beset over the whole sur- 

 face with small, densely crowded spines. The main stalk 

 of the bristle is fui*nished in the superior part of its ven- 

 tral side , over about ^/g of its total length , with small , 

 triangular, rather distant spines; opposite them the dor- 

 sal side shows a group of 9 to 10 much larger, ridge- 

 shaped teeth. Perhaps the exact shape of these bristles can 

 be gathered better from an inspection of the figures 3 , a 

 and h , than from any detailed description. 



Ac. Beddardi possesses in the vicinity of the sperma- 

 thecae still another kind of modified setae , about of the 



1) This Journal, Vol. IX, pi. 4, and pi. 5 fig. 3. 



N'otes from the Leyden Miiiseutn , Vol. X. 



