ZooL.— Vol. II.] 



RISEN— OLIGOCH^TA. 



241 



as in most other species; but posteriorly, where it would be 

 expected that micronephridia would be found, are large and 

 apparently typical meganephridia. Typical is used advis- 

 edly, as the condition of the specimen did not allow of 

 any very minute investigation. 



PERICH.^TIN^. 



Pontodrilus Perrier. 



Pontodrilus Michaelseni Eise?i, hortensis, var. nov. 



■ Definition. — Length 75 mm., width 3 mm. Prostomium encroaches 

 slightly on somite I. Setae with exceedingly faint transverse furrows. Sexual 

 zone depressed, with two parallel pits separated by a slight longitudinal ridge. 

 Anterior to this zone the clitellum is saddle-shaped. Spermathecse large, 

 pear-shaped, with narrow duct and a narrow, club-shaped diverticle. Pros- 

 tate with the muscular duct about two-thirds as wide as the glandular part. 

 The sperm-duct enters the glandular part near the muscular part and enters 

 the lumen at once. Intestine with a vascular crop in XIV and XV which is 

 strongly contracted at the septa. In other respects similar to the species. 



Habitat. — In garden soil, along sewers in the gardens of 

 Loreto, Baja California, Mexico, June 20, 1899. Many 

 specimens fully adult and with well developed clitellum and 

 sexual zone. The soil in the gardens is slightly saline, but 

 not to such an extent as to prevent the cultivation of oranges, 

 limes and bananas. The date palm thrives especially well. 

 No specimens were found near the shore. 



Sexual zone. Spermatheca. 



Detailed Description. 



Characteristics. — The principal differences between the 

 species and the variety are found in the sexual zone, the 

 form of the spermathecae, the faint ornamentation of the 

 set£e, and the relative size of the muscular and glandular 

 parts of the prostates. 



