164 PROCEEDINGS OF THE NATIONAL MUSEUM vol.84 



The ampulla of each spermatheca is of nearly spherical form and has 

 relatively thick walls with irregular folds present in the interior 

 surface. These folds are more prominent on the part of the wall 

 nearest the median longitudinal axis of the worm. 



MEGASCOLIDES CASCADENSIS, new species 



Distinguishing characters. — Length of preserved specimen, 185 mm. 

 Diameter, 5-7 mm. Somites, about 265. Setal distances, approxi- 

 mately aa: db:l>G: cd=l'\::2>:S:%\ dd in anterior region about two- 

 thirds of circumference and in posterior region about one-half of 

 circumference. Penial setae^ two pairs on 18, more than 1.5 mm long; 

 0.035-0.04 mm in diameter; each has a rather abrupt curve near the 

 outer end and very minute sculpturing; the remaining part is nearly 

 straight. The clitellum includes 13-20 and is incomplete ventrally. 

 Paired ventral papillae on 15/16, 16/17, 19/20, and 20/21. Sperma- 

 thecal pores on 7/8 and 8/9. Septa 6/7-11/12 most strongly thick- 

 ened. Calciferous gland with irregular diverticula extending into 

 the lumen in 10-15, reaching two-thirds of the distance to the middle 

 of the lumen in thirteenth somite and less in others. Sperm ducts 

 enter separately into prostate gland at the beginning of the prostate 

 duct. Spermathecae paired in 8 and 9. 



Material. — The only material available is an alcoholic specimen, 

 the holotype (U.S.N.M. no. 20243), received from F. M. McEl- 

 fresh of Salem, Oreg., in the autumn of 1899 with the statement that 

 it was collected in the Cascade Range in Oregon and with no other 

 data. Soon after the specimen was received transverse sections were 

 made of a piece including the lateral half of somites from the middle 

 of 14 to the middle of 19 as indicated by external characters, but the 

 internal parts were displaced somewhat posteriad, and the sections 

 included the alimentary tract and parts of the circulatory system 

 of the posterior part of the thirteenth somite. Transverse and sagit- 

 tal sections were also made of pieces near the posterior end. More 

 recently the anterior part of the specimen was split in the median 

 sagittal plane. A study of these parts and sections, and of the ex- 

 ternal characters of the remainder of the specimen, has supplied 

 data for the following description, which, though far from com- 

 plete, seems sufficient to warrant the recognition of a species dis- 

 tinct from those previously described. 



Extet^al characters. — The length is 185 mm, and the maximum 

 diameter anterior to the clitellum is 7 mm and posterior to the clitel- 

 lum 5-6 mm. In the middle of the clitellar region the diameter 

 is somewhat less than in adjacent parts. The number of somites 

 is about 265. Somites posterior to 5 are triannulate. The setae are 

 small and inconspicuous, with a length less than the thickness of 

 the body wall, and some are lacking. Tlie setal distances both 



