880 REPOET OF COMMISSIONER OF FISH AND FISHERIES. [2] 



A.— DESCEIPTIOK OF THE SPECIES OF TUBIFICID^. 



Oligochsetous, limicolide worms, with spines in fascicles, of which 

 four in each segment. One ventral and one dorsal longitudinal vessel, 

 the latter of which is pulsating. Both vessels are connected by trans- 

 versal gastric or perigastric vessels. Receptacles of the spermatozoa, 

 two in the ninth setigerous segment. Efferent ducts, two in the tenth 

 setigerous segment. Each duct famished with only one efferent funnel. 

 The oviduct is invagiuated by the penis. Habitat : Fresh or brackish 

 water. Two subfamilies, viz : 



Telmatodrilini : Atrium furnished with several prostata glands ; penis 

 and penis sheath united at apex. 



Tubifidni : Atrium with a single prostata gland ; penis and penis 

 sheath not united. 



L—Suh-/am. TELMATODRILINI, nov. fam. 



Atrium is surrounded with several prostata glands, not connected 

 with each other. 



The penis is connected with the penis sheath at its exterior apex. 



Oviduct is large, muscular, and opaque. 



The receptacle is situated in the ninth and the efferent duct in the 

 tenth setigerous segment. 



Nervous system. — The two longitudinal parts of the ventral nerve trunk 

 are connected by anastomosing, minute commissures. 



The spines resemble those of Enchytrceidce in general form, but are 

 more numerous in every fascicle and all of the same length. In young 

 specimens they are indistinctly forked. 



Of this family as yet only one species and genus is known, viz : 



Gen. TELMATODEILUS nov. gen. 



No distinqtly pulsating or differentiated hearts, but the secondary 

 vessels in the sixth to tenth setigerous segments are indistinctly pulsat- 

 ing, without having the shape of distinct hearts. The ventral vessel is 

 not strictly ventral, but pushed towards the dorsal side of the body, and 

 so near to the dorsal vessel that both seem to run close together ; the 

 ventral vessel not pulsating, the dorsal vessel pulsating. 



Only one si)ecies is as yet known, viz : 



TELMATODEILUS YeJDOVSKYI nOV. Sp. 



(Pis. I and II ; Figs, la to k.) 



Vascular system. — The ventral vessel is forked in the fourth setigerous 

 segment. The transversal or secondary vessels are of two kinds in 

 every segment, viz, gastric and perigastric. The perigastric vessel is 

 situated close to the posterior end of the segment 5 it sends to the integ- 

 ument of the body numerous minor tertiary vessels, forming together 



