No.nii5. PBOCEEDIXGS OF THE NATIONAL MISECM. 171 



Stiles ' excluded the known parasites of rodents from the genus Moniezia, 

 while Railliet proposed for the double-pored leporine forms the genus 

 Ctenota'iiia with Tamia marmotw as type. 



At first thought this genus does not appeal to helminthologists, who 

 have not paid special attention to the Anoplocephalinre, as being well 

 founded, but an anatomical study of the various forms does, 1 believe, 

 fully justify the separation of the double-pored cestodes of rodents 

 from the double-pored forms found in ruminants. The generic terui 

 Cittoticnia having priority must of course be accepted in preference to 

 CfenotcvHia. 



The characters of the three genera of double-pored anoplocephaline 

 forms, according to my present interpretation, are as follows: 



Diagnosis. — Moniezia., \l. Blauchard, 1891: AnoplocephalinoB with 

 segments generally broader than long and longer than thick; end seg- 

 ments showing a tendency to become longer and narrower. Two full 

 sets of genital organs, with two (very complex) reticulate uteri and two 

 lateral pores in each segment. On the right side the vagina is ventral, 

 cirrus dorsal; on the left side vagina dorsal, cirrus ventral. Dorsal 

 Ciinal lies dorso-median of ventral canal. Genital canals cross the lon- 

 gitudinal canals and nerves dorsally. Interproglottidal glands gener- 

 ally present. Calcareous corpuscles absent from i)arenchyma. Eggs 

 with well developed pyriform body, the horns of which generally 

 (always ?) end in a disk. 



Hosts. — Kuminants. 



Ti/pe. — Moniezia expansa (Eudolphi, 1810), R. Blanchard, 1891. 



For diagnosis of GittoUvnia, see above, p. 170. 



Diagnosis. — Thysanosoma, Diesing, 1835: Anoiilocephalinte with seg- 

 ments generally broader than long and longer than thick; end seg- 

 ments show a tendency to become longer and narrower. Two sets or 

 one set of genital glands and two lateral genital pores, or one lateral 

 genital pore to each segment; one transverse undulating uterus with 

 ascon- spore or cornucopia-like egg- pouches. Genital canals cross the 

 ventral canal and nerve dorsally, the dorsal canal ventrally. Interpro- 

 glottidal glands absent. Calcareous bodies absent from the paren- 

 chyma. Horns of pyriform body absent. 



Hosts. — Ruminants. 



Ty2^e. — Thysanosoma actinioides, Diesing, 1835. 



From this analysis of characters it will be seen that Cittotwnia forms 

 an excellent intermediate genus between Moniezia. and Thysanosoma. 



The genus may be divided into two groups: Marmotw or Denticulafa 

 Group and Pectinata Group, the division being based upon the form of 

 the cirrus pouch. In the first group this organ is pyriform, distinct and 

 very muscular ; in the second group it is more elongated, resembling the 

 nozzle to a hose, and is less distinct. 



'Centralbl. f. Bakteriol. u. Parasiteuk., XIII, 1893, p. 457; also, Bull. 4, Bureau 

 Animal Industry, 1893, p. 54. 



