ENCHYTR^ID^ 



91 



large anteseptal, almost equalling in size the postseptal lobe. So far 

 as I know, the latter type of nephridia has not been described in 

 JLunibricillus. 



SYNOPSIS OF SPECIES OF MARIONINA DESCRIBED IN THIS PAPER. 



I. Spermatheca without diverticles. 



Spermatheca with long duct and with an ampulla which is contracted at several 

 points. Interior of spermathecal duct ciliated. Ventral glands in X and 

 XI. Nephridia with large anteseptal i. M . alaskce ^-^ . nov , 



II. Spermatheca with two diverticles. 



Spermatheca with a long duct at the base of which are a few small glands. 

 Head-pore immediately in front of the groove between prostomium and 

 somite I. No ventral glands 2; M, americanas'^.tiov. 



MARIONINA ALASKA sp. nov. 

 p1. XIV, figs. 2-6; text-fig. 60. 



Definition. — Length 12 mm., width .'^'^ mm. Somites 53. Pros- 

 tomium blunt and rounded. Setae sigmoid : ventrals, 4, 6, 6, 7, 5, 6, 

 6, 5' 6, 4, o, 5, 4, 5, 4, 3, 4, 5, etc. ; laterals, 3, 4, 5, 6, 5, 5, 5, 5, 5, 

 4, o, 4, 4, 3, 3, 3^ 3i 4? 3» etc. Head-pore small between prostomium 

 and somite I. Dorsal pores ( ?) in II, III and IV. CHtellum dorsally 

 XII and XIII, ventrally XII, \ XIII. Sexual papillas distinct. Septal 

 glands in IV to VI. Dorsal vessel rises in XII. Intestine gradually 

 increasing in size ; no diverticles. Spermathecte large, with narrow, 

 strongly muscular duct and a wider ampulla, which is continued as a 

 narrow thin-walled duct until its junction with the intestine in VI/VII. 

 Sperm-ducts narrow and long. Sperm-funnels about three times as 

 long as wide. Penial bulb with two kinds of glandular cells opening 

 into the sperm-duct and around the pore. No ovisacs. Ventral glands 

 In X (and perhaps in XI). Nephridia with large antesejDtal in which 

 the duct is coiled. Lymphocytes large, circular and disc-shaped. 

 Color of alcoholic specimen yellow. No pigment. 



Locality. — Port Clarence, Alaska, Dr. Anton Stuxberg, Vega 

 Expedition (July 26, 1878). A single specimen. 



Characteristics . — The form of the spermatheca, with its narrow 

 duct connecting with the intestine, and with its three basal glands, 

 seems fully to characterize this species. 



DETAILED DESCRIPTION. 



On account of the want of specimens for dissection, the form of the 

 brain remains unknown. 



Body-wall. — The circular muscular layer consists of cells arranged 

 on the nematode plan as described by Hesse ( i ) . The plates are set 

 at a rather wide angle (p1. xiv, fig. 2). 



