462 THE ZOOLOGIST. 



3. Mesenchytreus oligosetosus, sp. nov. 



Description.— Length 5-6 mm. Segments 35. Setae 1-3 

 per set, never exceeding 3, usually 2 dorsal and 3 ventral. The 

 enlarged setae in segments 5 and 6, two in each lateral bundle. 

 Dorsal vessel arises apparently about 13/14. Nephridia with 

 small ante and large postseptal, the duct being about the same 

 length as the latter and arising near the septum. Brain incised 

 behind. Three pairs of septal glands. Girdle with large gland 

 cells on 12-1/2 13 ; moderately large ampulla for the size of the 

 worm, with large atrial gland and male pores, and long coiled 

 duct. No salivaries seen. Ccelomic corpuscles oval or ovoid, 

 some with processes at the two ends. The spermathecae were 

 not observed. 



The species has fewer setae than any whose descriptions I am 

 familiar with, hence the trivial name. Now described for the 

 first time. 



No genus is more perplexing than Fridericia. I have already 

 described a good many new species (see Bibliography), and 

 hesitate to multiply the number. Some of the Jersey forms are 

 very perplexing, and two at least are new to Britain. One of 

 them belongs to the group containing species with two setae in 

 each bundle throughout. The other merits separate description, 

 and is named after the discoverer. 



4. Fridericia hillmani, sp. nov. 

 Description. — Length 10-12 mm. Slender. Segments 50. 

 A second specimen was smaller than the type, but the characters 

 were the same. Setae 4 dorsally, 5-6 ventrally in front segments, 

 4 in segments 13-25, and 2 in posterior part of body. Sperma- 

 thecae with fairly large ampulla, duct two or three times as long, 

 and about 5 sessile diverticula. No 4/5 glands. Salivaries stout, 

 ends simple, but processes near the proximal end. Septals three 

 pairs. Girdle on 12-1/2 13, with roundish gland cells, long 

 slender coiled duct, and ampulla about 3x1. Dorsal vessel 

 arises about 18/19. Brain of normal shape and size with convex 

 posterior. Transparent between 9/10 and 13/14, clearly showing 

 the internal organs ; while the chloragogen cells in front are 

 large and brown. Nephridia of front segments with somewhat 

 globular anteseptal, and postseptal about three times as large. 





