262 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



EXPLy\NATION OF PLATE VII. 

 Pontoscolex corethrurus (Fr. Muller) mexicanus, subsp. nov. 



Fig. 24. Cross-section of a calciferous diverticle. Zeiss Apo. 2 mm., 1.40, 

 Oc. 4. 



Fig. 25. Cross-section of a calciferous diverticle at its connection with the 

 intestine. 



Fig. 26. Longitudinal section of the tubular intestine, where it opens into 

 the sacculated intestine, showing the thickened transverse muscu- 

 lar layer in somites XVI and XVII; ep., epithelial cells; those in 

 XVII ciliated. 



Eudrilus Eugenics (Kinberg). 



Fig. 27. Specimen natural size. 



Fig. 28. Anterior somites, dorsal view. 



Fig. 29. Clitellar somites, ventral view. 



Fig. 30. Exterior male apparatus, the copulatory bursa everted (side view). 



The narrow crescent-shaped penis is seen to encircle the large 



papilla on which opens the Y-gland. This papilla is contracted 



at the middle and pointed at each end. 

 Fig. 31. Male copulatory apparatus with the bursa everted (front view). 



Letters same as in fig. 30. 

 Fig. 32. A male copulatory apparatus with only partly everted bursa (front 



view). 

 Fig. 33. The same as above, side view, showing the groove, beginning 



about half-way between apex and base. The pore of the prostate 



is near the apex. 

 Fig. 34. Apex of penis showing groove and pore of prostate. 



Pontoscolex corethrurus (Fr. Muller) niexicanus, subsp. nov. 



Fig. 35. Lacking. 



Fig. 36a. Section of intestine showing typhlosole. 



Fig. 363. Detail of the typhlosole. 



Fig. 37. Transverse section of the upper part of the typhlosolar region, 

 including dorsal vessel, the chloragogen cells and intra-typhlosolar 

 canals; Zeiss Apo. 2 mm., Oc. 4; (a), the whole upper region 

 with a single central intra-typhlosolar canal; (b), a section of the 

 same region, but with two canals of unequal size; (c), a section 

 where an intra-typhlosolar canal opens into the upper part of the 

 intestine. Only part of the details are carried out, the indicated 

 parts being similar to those of fig. 37a/ in. ty. ca. , intra-typhlo- 

 solar canals; inv. cr. m., invagination of circular muscular layer 

 around the typhlosole. 



Fig. 38. Lacking. 



Eudrilus Eugenics (Kinberg). 



Fig- 39- The two median diverticles of the intestine in somites X, XI, show- 

 ing the very narrow connection with the intestine as well as their 

 relative size (longitudinal section); sub. in. v. subintestinal ves- 

 sel, not divided in any part of the somite. 



