ENCHYTR^EID^E 



S3 



in IV to VI. Spermatheca cylindrical, with two opposite diverticles 

 on the quarter nearest the intestine. Sperm-ducts about ten times as 

 long as the funnel, furnished with a bottle-shaped enlargement near 

 the pore. No atrial glands. The funnel is very large, three- or four- 

 lobed. Dorsal vessel rises in somite XIX. Sperm-sacs in XII to 

 XVI. Ovisac extends to XVIII. Nephridia with three principal 

 lobes, the general shape deltoid. Lymphocytes very large, oval. 

 Blood orange red. 



Locality. Pine Ridge above the toll-house road near the lumber 

 mills, Sierra Nevada, Fresno County, California. Found among 

 decaying leaves and in the mud in the running water of a small tribu- 

 tary to Rush Creek, the latter being a tributary to Kings River. A 

 truly aquatic species. July and August. Altitude about 7000 feet. 



Characteristics. Readily dis- 

 tinguished by its large lympho- 

 cytes, the shape of the lower end 

 of the sperm-ducts and the sperm- 

 atheca. The diverticles of the 

 latter are situated much nearer 

 the intestine than in M. pedatus. 



DETAILED DESCRIPTION. 



Sperm iducal appa ra tus . At- 

 rium does not appear to possess 



any atrial glands. There are nu- 



. ... ... FIG. 27. Mesenckytrceus fontinalis. 



merous large glands which sur- 

 round the atrium but which open exteriorly to the bulb, around the 

 latter's base. Numerous oblong and very thin penial glands inside the 

 bulb. The bulb is small and possesses fewer muscles than most other 

 species of the genus. On account of the insufficient fixation of the 

 specimens the finer details of the penial bulb could not be made out as 

 well as might be desired. The atrium is large and furnished interiorly 

 with an epithelium consisting of large cubical cells (pi. xi, fig. 3). The 

 funnel is large, occupying more than half of the somite when viewed in 

 a longitudinal section of the body. When dissected it is seen that the 

 funnel consists of three or four clefts, like those of an orange partly 

 split open. The sperm-duct, which runs first upward, then back- 

 ward, through about four somites in a more or less twisted manner, 

 must be at least ten times as long as the funnel. The exterior papilla 

 is quite low. 



Septal glands. These are large and of the same shape as in J/. 

 pedatus. Part of the glands adhere closely to the posterior septum 



