ZooL.-VoL. II.] EISEN—OLIGOCH^TA. 133 



Mucocytes. — The round cyanophile cells found in great 

 numbers in the lymph are probably referable to the class 

 called by Dr. Rosa mucocytes. They are, however, per- 

 fectly round and have not the projections figured by Rosa. 

 They are of the same size as the nematocytes but are 

 spherical and even in outline, and furnished with a cell-wall. 

 The nucleus is round with a central nucleolus. The muco- 

 cytes are more numerous than anj- of the other cells and 

 appear to originate in a special lymphatic tissue intimately 

 connected with the septal glands in VII, VIII and IX. It 

 is not found surrounding the glands in IV, V or VI. The 

 real septal glands in VII-IX are small, but appear much 

 larger than they are on account of this lymphatic layer, 

 which closely and intensely surrounds the cellular tissue of 

 the glands. The differentiation is best brought out by a 

 double stain of Rubin S. and Toluidine blue, the gland 

 staining dark blue and the lymphatic tissue pink with blue 

 nuclei. The cells composing this lymphatic tissue are not 

 as round as the mucocytes. There are large numbers of 

 the latter embedded in the tissue, especially at the edges, 

 where probably they originate, though I have not seen any 

 of them in mitosis. 



Amcebocytes. — These are small star-shaped bodies with 

 minute and numerous thread-like pseudopodia. These rods 

 or threads are probably the amoeboid projections of the cell 

 itself, but the whole structure is too small to be studied in 

 detail. They stain but poorly, and are less readily studied 

 than the nematocytes. 



Subgenus Ilyogenia Beddard. 

 Ocnerodrilus (Ilyogenia) taste Eisen. 



Plate XIV, Figs. 157, 158. 



Phcenicodrilus taste Eisen, Mem. Cal. Acad. Sci., Vol. II, 1895-96, Nos. 4 

 and 5. 



Hahitat. — In the immediate vicinity of the city of Tepic, 

 Mexico, at an altitude of 4,000 feet. Also numerous speci- 

 mens collected by Prof. Albert Koebele in the vicinity of 



