British Tuhificidn}. By Rev. H. Friend. 289 



Segmental- geht je eine vielfach verschlungene Schleife vom Riicken- 

 zum Bauchgefass. 



" Keines tier zalireichen vorgefundenen Exemplare war ge- 

 schlechtsreif, so dass auch hier die Beschreibung zii erganzen ist. 

 Die gegebenen Anhaltspunkte ermoglichen jedocli unzweifelhaft, 

 das Objekt wieder zu erkeimen. Fimdort : Langensee bei Ascona." 



1900. — Eevue Suisse de Zool., viii. p. 447, fig. 4. 



The Ilyodrilits filiformis of Ditlevsen is (as already stated) the 

 same as Rlu/acodrilus falciformis Bret. 



There are points of resemblance between this species and Ryo- 

 drilufi palusti'is Dit. (Zeitschr. wiss. Zool., Ixxvii. (1904) p. 408) ; but 

 if his drawings are correct, the teeth of the setffi differ widely from 

 those of /. i)allescens. 



Ryodrilus meganymphus sp. n. 



A clear, transparent worm, with large spherical, blackish 

 coelomic corpuscles, like those of Rhyacodrilus, profuse, and very 

 characteristic, about oue-third or one-quarter the length of the 

 set* in diameter. Length about 20 to 25 mm. 

 (=1 in.), with 60 segments. Chloragogen cells 

 begin in the unusual position of segment 4. The 

 brain (fig. 52) with four almost equal lobes or 

 processes behind, palmate, or resembling a hand 

 with four large fingers, setse of two kinds, capilli- 

 form and forked. Usually 1 cap. seta and 2 forked 

 setee in segments 2-3 dorsally and 3-5 ventrally. 

 Capilliform setae die out behind segment 30, and 

 forked setse number 3 or 2 posteriorly, with teeth Fig. 52. 



short and equal. 



I saw no enlarged hearts in 8 or 9, and the vascular system in 

 front was almost identical with that found in Enchytrffiids, so 

 that this worm may be regarded, perhaps, as a link between the 

 red-blooded Enchytneids (as Marionina or Pachydrilus) and the 

 Tubificids. The head pore, which is situated on the prostomium, 

 midway between the tip and the septum, is matched by another 

 worm which I found in the same locality. The pharynx is in 

 segments 2-5. 



The striking characteristics are the brain, ccelomic corpuscles, 

 head pore, forward origin of the chloragogen cells, setae, simple 

 vascular system without hearts, and the position of the pharynx. 



VII. Genus Branchiura Beddard. 

 Branchiura Sowerbyi Beddard. 



Eestoring B. coocinea to its rightful place under llyodrilus, we 

 have only one species of Branchmra at present. It occurs at 



