56 PROCEEDINGS OF THE NATIONAL MUSEUM. ^l. 55. 



In the same paper (Hall, 1910) I stated that the parasite appar- 

 ently did not occur in Germany. Later information is to the same 

 effect. It would be interesting to know why a parasite which occurs 

 in France, Switzerland, Italy, Russia, and Siberia does not, appar- 

 ently, occur in Germany, Austria, and Hungary, in spite of the fact 

 that primary and secondary hosts are present in the countries in ques- 

 tion, and so far as any one knows, under circumstances presumably 

 as favorable as in the countries in which the parasite is found. 



Genus ECHINOCOCCUS Rudolphi, 1801a. 



Synonyms. — Acephalocystis Laennec, 1804; Liococcus Bremser, 

 1819« ; Splanchnococcus Bremser, 1819a ; Echinohokkus Buhl, 1856a ; 

 Echinococcifer Weinland, 1858*2. (For additional synonyms see 

 Stiles and Stevenson, 1905a.) 



Generic diagnosis. — Taeniinae: Strobila composed of not over four 



or five segments, of which only the posterior terminal segment is 



gravid. Head armed with a double crown of 



hooks. Genital pores marginal and irregularly 



alternate. Larval stage an echinococcus, a blad- 



FiG. 56.- Echinococcus derwomi with a thick laminated Avail and Avith 



GRANULOSUS. LARGE qj^. v/itliout intcmal or external daughter cysts: 



AND SMALL HOOKS. . " .'J 



X300. After leuck- brood capsules develop in the mother or daugh- 

 ART, 1880. ^^^ cj'sts and contain several scolices. Adults in 



carnivorous animals; larval stage in herbivorous and omnivorous 



animals. 



Type-species. — Echinococcus granulosus (Batsch, 1786a) Rudolphi, 



1805a. 



ECHINOCOCCUS GRANULOSUS (Batsch, 1786fl) Rudolphi, 1805a. 



Synx)nyins. — Taenia echinococcus Siebold, 1853 ; Echinococcifer 

 echinococcus (von Siebold, 1853) Weinland, 1861; Taenia echinococca 

 Koeberle, 1861a; Taenia {Echinococcifer) echinococcus of Leuckart, 

 1863; Taenia {Arhynchotaenia) echinococcus of Diesing, 1864a; 

 Taenia echinoccus von LinstoAv, 1878; Taenia {Echinococcus) echi- 

 nococcus of Railliet, 1885a. (For additional synonyms, see Stiles, 

 1906a.) 



Specific diagnosis. — Echinococcus'. Head very small, subglobular, 

 scarcely 300 /* in diameter. Rostellum prominent, armed with a double 

 crown of 28 to 50 booklets. The large hooks (fig. 56) are 22 to 30 /* 

 long (40 to 45 yu,, according to Leuckart). They have a blade of very 

 slight curvature, which tends to lie in a prolongation of the longi- 

 tudinal axis of the handle, and which is very thick at the base; the 

 handle is rather straight, short, and thick, and with dorsal and 

 ventral swellings in the median portion; the guard is excessively 

 shortened and rounded, forming practically a hemispherical protu- 



