272 O LI GOGH A ETA 



Genus EMBOLOCEPHALUS, RANDOLPH. 

 Syn. Saenuris, GEUBE (in part.). 



DEFINITION. Setae of dorsal bundles capilliform alone or with uncinate setae 

 also. Anterior segments retractile. Non-retractile sense-organs in rows round 

 the segments. Live in a tube fabricated by themselves. Spermiducal glands as 

 in Tubifex. 



This genus was formed by RANDOLPH (1) for GRUBE'S Saenuris velutina and 

 a new species congeneric with it ; the two species thus associated differ from each 

 other in a number of points but agree in the characters given in the above definition ; 

 the most remarkable feature of the genus appears to be the complete retractility of 

 the first two or three segments of the body ; of less importance are the sense organs 

 which RANDOLPH compares to those of Slavina; they also resemble those of Spiro- 

 sperma. The genus is doubtless, as its clescriber suggests, intermediate between the 

 Tubificidae and the Naidomorpha ; Embolocephalus velutina has, as have some of the 

 Naidomorpha, only capilliform setae in the dorsal bundles ; in the other species, how- 

 ever, the setae are like those of other Tubificids. The most remarkable internal 

 structure of the genus is found only in E. velutina; in this worm are a pair of glands 

 associated with the ventral setae of the tenth segment ; these glands have a lining of 

 glandular cells, and attached to the outside is a mass exactly like the ' prostate ' 

 of other Tubificids : in fact the whole gland exactly resembles the spermiducal gland 

 in most other members of the family. There is no doubt in my mind that it is to 

 be compared to the albumen gland of the Lumbriculidae ; and its presence thus cements 

 more closely the union between the families Tubificidae and Lumbriculidae. 



(j) Embolocephalus velutinus (GRUBE). 



Saenuris velutina, GRUBE, JB. Schles. Ges. vat. Cult., 1878, p. 116. 

 E. velutina, RANDOLPH, Vierteljahrsch. nat. Ges. Zurich, 1892, p. 147. 



Definition. Length 50 mm. ; number of segments 70. Tico rings of sense-papillae in each 

 segment, one on a level with setae the other on a level with the septa. Dorsal setae all 

 capilliform, two, three, or four to a bundle ; ventral bundle consists of two nncinale 

 setae, not always with well-marked cleft at end. Brain concave in front with two 

 posterior lobes. Clitellum X-XII. In segment X a pair of large glands connected wi/h 

 ventral setae. Hob. Lakes of Zurich and Geneva. 



