ENCHYTR^ID^ 



49 



as the spokes in a wheel, and between the strands are a number of small 

 unicellular glands opening near the pore. Besides these very small 

 glands, there are also a dozen or more larger glands which rise 

 high above the muscular strands (p1. viii, fig. 5), and which seem 

 to open near to the apex of the penis. There are thus three sets 

 of glands opening in connection with the sperm-ducts : atrial glands 

 and two kinds of penial glands, the smaller of which do not rise 

 above the muscular strand mentioned above. The funnels are thick 

 and helix-like (fig. 22, <5), and taper very gradually into the sperm- 

 ducts. The sperm -sacs are long and thick, extending from the ventral 

 to the dorsal side of the ccelom. 



Nephridia (fig. 23) are round with two principal folds with rounded 

 outlines. The duct leading to the pore is thick and helix-like. 



Lytnphocytes few in number, of disc-like form, and quite small. 



Ijttestine. — The intestine, both posterior and anterior to clitellum, 

 is covered with a thick coating of brown chloragogen cells. 



MESENCHYTR^US FUSCUS INERMIS var. nov. 

 pi. I, fig. 18; text-fig. 24. 



Definition. — Length about 20 mm., width about i mm. Somites 

 75. Setae sigmoid : laterals ; 3, 4, 3, o, 5, 6, 5, 6, 6, 7, 6, 5 (4, 3, 2) ; 

 ventrals; 4, 5, 6, 5, o, 6, 6, 4, 6, 7, 6, 5 (5, 4). Head-pore halfway 

 between apex and the first groove. Clitellum ventrally and dorsally ^ 

 XI-XIII. Sexual papillae not large. Sep- 

 tal srlands in IV to VI. Brain as in the 

 species, but less emarginated anteriorly. 

 Dorsal vessel rises in somite XXI. Intes- 

 tine narrower in II and III. Spermatheca 

 with two diverticles near the base, each 

 being two-elevenths as long as the whole 

 spermatheca. Sperm-ducts about twelve 

 times as long as the length of the funnel. 

 Funnel more slender than in the species. 

 An atrium present, in which open four to 

 six glands near its junction with the penis. 

 Penial glands open near the penis. Sperm- 

 sacs very large, extending as far back as 

 XXII. Ecrg-sac extends at least to XXVIII. 

 Testes and ovaries normal. Nephridia 

 less round than in the species. Lymphocytes small and ovoid. 



Fig. 24. Mcscnchytraus fuscus 

 var. inermis. 



