T^NIOID CESTODES OP NORTH AMEEICAN BIRDS. 69 



69. Uterus not persistent, the eggs becoming isolated in tlie parencliyma mostly 



in tlie lateral fields of the segment, few in the median field; testicles 

 in lateral fields, absent from the median field ; adults in reptiles. 



Pancerina, p. 85. 

 Uterus persistent 70 



70. Uterus single or double (one on each side of median line), transversely 



elongated, tubular, generally with simple anterior and posterior out- 

 pocketings ; vagina ventral of cirrus pouch on both sides of segment ; eggs 

 with or without pyriform apparatus ; adults in mammals and birds. 



Cittotcenia, p. 63. 



Two reticulate uteri which may become more or less fused with one another 



in the median line ; vagina ventral and cirrus dorsal on right-hand side of 



segment, vice versa on left side; eggs with or without pyriform apparatus; 



adults in mammals and birds Moniezia, p. 64. 



DIAGNOSES OF FAMILIES, SUBFAMILIES, AND GENERA, AND LISTS OF SPECIES OCCUR- 

 RING IN NORTH AMERICAN BIRDS. 



Under each genus are listed the species which have been reported as 

 parasites of North American birds, and references are given to articles 

 in which descriptions of these forms may be found. Species which 

 have been collected in this country, and of which I have examined 

 specimens, are indicated by an asterisk, and the names of hosts from 

 which such specimens were collected are indicated in a similar 

 manner. Among the hosts are included a number of species which 

 are not North American, comprising (1) forms which have been in- 

 troduced, such as the English sparrow and various game birds, (2) 

 forms which are present in this country in the domesticated state, and 

 (3) forms which are represented in the North American fauna by 

 varieties or subspecies. 



Family TETRABOTHKIID^. 



Tetradothridce Diesing, 1850, in part. 



Family diagnosis. — Tsenioidea : Scolex unarmed, without rostellum. 

 Suckers with an outwardly projecting auricular appendage on the 

 anterior border. Neck short. Segments of the strobila, with the 

 exception of the hindermost segments, always much broader than 

 long. A single set of reproductive organs in each segment. Genital 

 pores unilateral. Genital cloaca deep. Cirrus pouch small and nearly 

 spherical, united with the genital cloaca by a muscular cloacal canal. 

 Yolk gland in front of the ovary. Eggs with three transparent en- 

 velopes. Adults in birds and mammals. 



Type-genus. — Tetrahotkrius Rudolphi, 1819. 



Genus TETRABOTHRIUS RLidolphi, 1819. 



Amphoterocotyle Diesing, 1863 (type, A. elegans Diesing, 1863). 

 ProstJwcocotyle Monticelli, 1892 (type, Tcenia forsteri Krefft, 1871). 

 Bothridiotcenia Lonnberg, 1896 (type, Tcenia erostris, Lonnberg, 1889). 



