18 PROCEEDINGS OP THE NATIONAL, MUSEUM vol.75 



All of the specimens except the type have a second large pair of sem- 

 inal vesicles in segment x as well as xi. The prostates are flattened 

 strap-shaped glands. The inner edge is straight, the outer edge 

 incised, especially posteriorly. The duct is 1-2 mm. long, thin,, 

 flattened, and passes straight into the parietes. 



The spermathecal duct is stout. The diverticulum is longer than 

 the ampulla and duct together, narrowly tubular, bent in various 

 ways, and only very slightly enlarged at the free end. The ampulla 

 is roughly heart-shaped. 



In coloration and general external appearance this worm is very 

 similar to N. depressus. The two forms are readily differentiated, 

 however, by the setal intervals, and the character of the ridges bear- 

 ing the seminal grooves. N. lunatus appears to be much rarer than 

 the other species as only eight specimens were secured. Four of the 

 eight are short, broken-off head portions. Fifty-eight specimens of 

 the other species were secured. 



PHERETIMA MINUTA, new species 



Description oj the type-specimen, external characteristics (GateS' 

 collection). — Length, 43 mm. Diameter, 2-2}^ mm. Number of 

 segments, 90. Color: Unpigmented, very light grayish white, 

 slightly darker on the dorsal surface anterior to the clitellum than 

 elsewhere, clitellum pinkish. 



The prostomium is epilobous, the tongue on segment i is short. 



On segments v-ix, inclusive, there is a single deep secondary furrow 

 posterior to the setae of the segment. On x-xiii there are two 

 secondary furrows per segment, one anterior to and the other pos- 

 terior to the setae of the segment. The setae are on ridges which 

 are marked off, behind the clitellum, by more or less complete 

 secondary furrows. 



The first dorsal pore is in 12/13. 



The setae begin on segment ii. The setal numbers are; v-32, ix-36,, 

 xii-37, xix-36. As a rule there is no break in the setal circles in the 

 ventral region and the dorsal break is very slight. The last three 

 segments have no setae, and the fourth segment from the last has 

 only sLx setae, all in the ventral region. 



The clitellum extends from 13/14 to 16/17 (3). It is ring shaped 

 and complete on all the segments. Dorsal pores and intersegmental 

 furrows are lacking; on the ventral side of segment xvi there are 

 four setae. 



The male pores are on segment xviii at the center of small round 

 papillae, separated by 10 setae. The papillae have flat surfaces dis- 

 tinctly marked off by a circumferential furrow and are seated on very 

 slight conical swellings in the body wall in the setal circle. 



The female pore is on a small whitish oval area on xiv. 



