medium size, with about sixteen large gland-fascicles opening at the 

 entrance of the atrium into the bulb. One set of penial glands 



inside the bulb. Sperm-sacs extending back 

 some thirty somites. Nephridia with two 

 principal lobes and with a small urinary 

 bladder at the pore. From this bladder down- 

 ward the duct is repeatedly twisted, and at 

 least once branched. Color yellowish, with 

 brownish flush on the dorsal side owing to 

 pigment. 



Locality. This, the most gigantic of all 

 the Enchytraeids, so far as now known, seems 

 to have an extensive distribution in Alaska, 

 and may possibly reach even as far south as 

 California. Years ago I found a gigantic 

 Mesenchytrceus at Horse Corral Meadow in 

 the Sierra Nevada of Fresno County, Cali- 

 fornia. The specimen was unfortunately 

 lost before I could describe it, but the sim- 

 ilarity to M. harri- 

 mani is so great 

 that it is not impos- 

 sible that the two 

 are identical. The 

 elevation of Horse 

 Corral Meadow is 

 maybe about 7,000 

 feet, so that the al- 

 titude would make 



up for the latitude. Of course it is impos- 

 sible to know whether or not the specimen 

 was identical with M. harrimani, but the 

 outward appearance, so far as I can remem- 

 ber, certainly was the same. The Alaska 

 specimens were collected by members of 

 the Harriman Expedition, principally as fol- 

 lows : By Prof .W. E. Ritter, Kadiak, Alaska, 

 August, 1899; by Prof. Trevor Kincaid, 

 Orca, Alaska, June, 1899; Metlakatla, June 

 4 ; Sitka, June ; Lowe Inlet, British Columbia, June ; Yakutat, Alaska. 

 I possess also several adult specimens collected by Prof. W. A. 



FIG. 5. Mesenchytrceus 

 Jtarrimani. 



FIG. 6. Mesenchytrceus 

 harrimani. 



