44 



EISEN 



The atrial glands push through the bulb, but their larger part lies 

 free in the coelom. There are five or six penial glands inside the bulb, 



opening around the penial 

 jDore. The funnels are (in 

 the single specimen) en- 

 gaged in the sperm-sacs. 

 They are turned backward 

 and lie in somites XII and 

 XIII, instead of in IX, as is 

 usually the case. The atrial 

 glands seem to open mainly 

 on the concave side of the 

 atrium. p1. ix, figs, i and 



Fig. 19. MesenchytycEus penicillus. 



2, are somewhat diagrammatic, but represent correctly, in a general 

 way, the spermiducal apparatus. 



Nephridla (fig. 19). — The outlines are rounded and the lobes 

 quite shallow. The nuclei are nearly round and of different sizes. 

 The lyi7iphocytes are not known. 



MESENCHYTR^US GRANDIS sp. nov. 

 p1. I, figs. 8-10; pi. VII, figs. 1-6; text-fig. 20. 



Definition. — Length 170 mm., width behind clitellum 1.75 mm., 

 clitellum 3.25 mm. Body strongly tapering, especially toward the tail. 

 Somites 105. Setae : ventrals, 3, 4, 5, 6, 5, 6, 6, 6, 5, 5, o, XIII, i, 

 5, 6, 6, 5, 5 ; laterals, 2, 3, 4, 4, 3, 4, 3, 4, 3, o, XIII, i, 4, 4, 4, 5, 

 4, 5. Clitellum very prominent. Prostomium rounded, with a large 

 head-pore far forward. Sexual papillge distinct, but not large ; ovi- 

 pores prominent. Septal glands in IV to VI. Brain posteriorly 

 slightly emarginated, a little longer than broad. Spermatheca^ thick, 

 with two long club-shaped diverticles, as long as the duct, ampullar 

 part short. Intestine and dorsal vessel covered with short but dense 

 chloragogen cells. The dorsal vessel rises posterior to XX. Sperm- 

 ducts about three times as long as the funnels, which latter are un- 

 usually long, extending through some six somites backward. The 

 lower part of the sperm-duct with a long and narrow atrium and a 

 large penial bulb. In the atrium open some seven or eight long glands. 

 Some twenty or more penial glands open around the base in the penial 

 bulb. Ovaries and testes absent in the single specimen. Ovisac be- 

 gins in XVII. Nephridia thick ; broad anteseptal ; postseptal with 

 three folds ; posterior duct thin, nuclei very small, ovoid. Lympho- 



