2 PEOCEEDINGS OF THE NATIONAL MUSEUM vol.66 



colonies, the latter branching in typical dendritic fashion. The 

 cysticerci enter into the lung tissue by basal stalks or peduncles, 

 which in the case of single cysticerci penetrate directly into the 

 lung substance, and in the case of colonial cysticerci, are connected 

 to larger stalks which ultimately penetrate into the lung. Head 

 invaginated, 0.9 mm. wide in press preparation, armed with a 

 double row of hooks, consisting of 18 large hooks and 18 small 

 hooks (fig. 1). The large hooks (fig. 2a) are from 189/x to 198/* 

 long. They have a blade of marked curvature, a handle which 

 is long and thick and which is only slightly sinuous in outline on 

 its dorsal surface, the ventral surface being smooth. The dorsal 

 surface of the handle forms a continuous line with that of the 

 blade. The surfaces of the handle are almost j)arallel, the posterior 

 end of that structure being bluntly rounded. The guard is strik- 

 ingly long, bifid, and conical in shape, its maximum diameter being 

 in the region of its union with the blade and handle. The small 

 hooks (fig. 2Jj) are from 155[jl to 163[i. long. They have a strongly 

 curved blade whose dorsal margin forms a continuous line with 

 that of the handle. The latter has parallel margins and a rounded 

 posterior end. The guard is bifid and has a bluntly rounded end. 

 The suckers are elliptical in shape and have a maximum diameter of 

 165/-1 to 185/x. 



Host. — Erethizon epixanthum. 



Location. — Lung. 



Locality. — Ophir, Alaska. 



2'ype specimen. — United States National Museum Helminthologi- 

 cal Collections, No. 26003. 



The mode of branching is shown in figure 3. Two of the 

 cysticerci are attached directly to the lung tissue (6), and so far as 

 can be seen, have no connection with the remaining cysticerci which 

 form a branching colony. The latter is connected by a stalk (s) 

 that emerges from the lung substance and divides into two main 

 branches, one branch {x) bearing a developed cysticercus and two 

 small buds (c) growing out in the region of the base of the cysticer- 

 cus. llie second branch {y) bears several developed cysticerci and 

 several small buds. The cysticerci converge to a more or less com- 

 mon origin, each cysticercus being connected to the main branch by 

 means of a peduncle, with a single exception {a) in which two 

 cysticerci are connected by a single peduncle the two bladders being 

 joined about half way above their point of origin. The two isolated 

 cysticerci (&) occur singly without buds or branches. 



Multiplication of larval cestodes by means of budding is known to 

 occur in Sparganuvi, in cysticercoids and in coenuri, is the rule in 

 Echinoccus, and has been noted in cysticerci. A variety of Cysticer- 

 cus cellulosae that exhibits the phenomenon of proliferation is fre- 



