ENCHYTR^IDjE 



the cells are longer and closer together (pi. n, fig. i). The unicellular 

 glands open partly inside the atrium, all along the surface marked * xx ' 

 and ' xxx.' Partly also on the free, exterior surface marked ' x' in pi. 

 n, fig. 5. The cytoplasm of the epithelial cells in question is striated, 

 making it still more difficult to distinguish the free cell-tips, especially 

 in indifferently fixed material. 



Spermathecce (figs. 40? and 5) . Spermathecae unusually elongated, 

 extending as far back as somites X or XI. In each somite there is a 

 bulging out of the ampulla, each such sac-like part being separated 

 from the one in the adjoining somite by the constriction caused by the 

 septum. The last two swellings of the ampulla are larger than the 

 others, as wide as the funnels of the sperm-ducts. No connection with 

 the intestine. The spermathecae resemble greatly those of M.francis- 

 canus, except as regards 

 the diverticles, which in 

 M. harrimani are heavier 

 and not as long. 



MESENCHYTR^US 

 SETCHELLI sp. nov. 



pi. I, fig. ii ; pi. iv, figs. 1-3; 

 and text-figs. 7-9. 



Definition. Length 

 12 mm, width .8 mm. 

 Somites, 70. Prostomium 

 pointed. Seta? : laterals, 



4 4> 4> 3i 4> 5 3> 5 4> 



4, o (XII), 2 (XIII), 4, 



4> 3> 3> 4> 4, 4> 4> etc., 

 3, 2, 3, 2 ; ventrals, 4, 5, 



6, 7> 7, 7 6 > 5, 5i 5, o 

 (XII), 5 (XIII), 5, 5, 4, 



5, 6, 6, 6, 4, 5, 4, 4, 4. 

 Setae facing the lateral 

 interval smaller; increase 

 gradually in size toward 

 the ventral and dorsal in- 

 tervals. Clitellum | XI 

 to XIII, with deep inter- 



FIG. 7. Mesenchytrceus setchelli. 



segmental grooves. Sexual papillae small. Septal glands large, in 

 IV to VI. Brain anteriorly deeply concave, posteriorly convex; 



