ENCHYTR^ID^ 



95 



confined to somite XII. Funnels large, longer than wide, In XI. No 

 sperm-sacs and no ovisacs. No prostates, but small and numerous 

 penial glands confined by the peritoneum and the penial bulb. No 

 ventral glands. Ovaries in XII and testes in XI. Nephridia with 

 a short anteseptal, a rectangular central lobe, and a long duct. Lym- 

 phocytes round, flat, about one-third the width of the short diameter 

 of the nephridium. 



Locality. — Port Clarence, Alaska, July 23-26, 1878. Dr. Anton 

 Stuxberg, Vega Expedition. 



Characteristics. — This species is readily distinguished from the 

 type species, B. ehlersi., by its large intestinal diverticles, its brain, 

 which is emarginated both posteriorly and anteriorly, and by its setae, 

 which are so short that they cannot be studied on undissected speci- 

 mens. Their number is also characteristic, there being only two in 

 each bundle. 



DETAILED DESCRIPTION. 



Size. — It is remarkable that the relative length and width should 

 vary to such extent that with the same length some specimens are but 

 half as wide as others. I suspected at first that I had before me two 

 distinct species, but I am unable to distin- 

 guish any characteristics that would ac- 

 company the difference in size. There 

 are in all eight specimens in the collection, 

 two of which are thick, the others thin. 

 One of the thick specimens was sectioned 

 longitudinally, while of the thin ones one 

 was sectioned transversely and one was 

 dissected. 



Somites. — The body is of an even thick- 

 ness and the somites though distinct are 

 hardly set off from each other, the inter- 

 segmental grooves being exceedingly shal- 

 low. This gives the body a smooth, even, 

 and glossy appearance. It is to be remarked that the thin speci- 

 mens possess the largest number of somites. 



Setce. — The sette are not distinctly sigmoid but almost straight. 

 They are also very short (p1. xii, fig. 3«). They begin with somite 

 II, and are arranged in couples, there being thus eight in each somite, 

 except in the last, where there are only four. 



Copulative organs. — The exterior papilla short, broad and truncate, 

 with a longitudinal slit at the apex into which open the sperm-duct 



Fig. 63. Bryodrilus udei. 



