46 ILLINOIS BIOLOGICAL MONOGRAPHS [396 



tory ducts dorsally or not at all. These points should be stated in the 

 diagnosis of the genus. 



The diagnosis therefore becomes as follows: 



Anoplocephalinae, with segments generally broader than long. 

 Two complete sets of reproductive organs in each segment, or with but 

 one continuous uterus. Uterus generally reticular, either confined to 

 the median field or crossing the excretory ducts dorsally only. Oviduct 

 joins with ovary directly in front of the middle of the vitelline gland. 

 Genital canals cross on dorsal side of longitudinal excretory vessels and 

 nerves. Interproglottidal glands often present. Vagina ventral and 

 cirrus dorsal on right side of the proglottid; the reverse on the left 

 side. Pyriform apparatus present or absent; when present, the horns 

 end in a disk. Adults in mammals and birds. 



Type-species : Monieza expansa Rudolphi 1810. 



THE CITTOTAENIAE OF NORTH AMERICAN RABBITS 



There have been described and named as parasites of North Ameri- 

 can rabbits four Cittotaeniae, namely, C. perplexa, C. mosaica, C. pecti- 

 nata, and C. variabilis. Of variabilis I had at hand the material studied 

 by Lyman (1902) and several specimens I collected at various points 

 in Kansas and Oklahoma. The observations confirm Lyman's state- 

 ments and need be discussed no farther. A drawing is given (Fig. 44) 

 for purposes of comparison. 



Of C. pectinata there is at hand Lyman's material from Kansas 

 and Nebraska and also two individuals which I collected at Neosho 

 Falls, Kansas. I have been unable to find any confirmation of Lyman's 

 statement that the uterus in anlage extends beyond the excretory ducts. 

 Stiles (1896) and Hall (1908) also conclude that it does not. In some 

 instances I have observed that the fully developed uterus extends 

 slightly beyond the excretory ducts dorsally; but usually it is confined 

 to the median field at all stages. Lyman states that the greatest diame- 

 ter of the lobes or pouches of the ovary is 16/*. My own measurements 

 of Lyman's material and my own show a diameter of 40 to 60/u. as the 

 usual condition. Since the ova themselves are 15 to 18jn in diameter 

 his figures seem most probably a typographical error. 



The specimens taken at Neosho Falls, Kansas, are in some respects 

 quite different from Lyman's. The testes are practically absent from 

 the middle part of the proglottid and somewhat more numerous in the 

 lateral parts than in Lyman's material. These two specimens which 

 have shed some proglottids are 45 mm. long and consist each of 85 

 proglottids. Lyman's specimens were up to 71 mm. long and had when 



