NO. 1105. PROCEEDINGS OF THE NATIONAL MUSEUM. 183 



Head unarmed, not very distinct from strobila, 0.43 mm. broad by 

 0.32 mm. long ; rostellum not observed 5 suckers 0.16 mm. long by 

 0.128 mm. broad. Neck short and broad. Segmentation begins about 

 0.56 mm. from the anterior extremity of head. About 150 proglottids 

 present, very distinct; the posterior flap overlaps the anterior one-third 

 to one sixth of the next following segment. Genital pores double and 

 opposite, not prominent, in about the middle of the lateral margin. 

 Male organs: Testicles numerous, confined to dorsal portion of median 

 field; cirrus pouch dorsal of vagina ou both sides of segment, 0.24 mm. 

 long, muscular, containing globular receptaculum seminis (about 90 ^ 

 diameter) in its proximal portion; it extends to or slightly beyond the 

 ventral canal. Female organs: Female glands about halfway between 

 median line and ventral canal; vagina narrow, extends across ventral 

 canal, then dilates into a large receptaculum seminis; uterus probably 

 single, possessing blind proximal and distal pouches. Ova, 32 to 36 u 

 in diameter; bulb of pyriform body, 8 to 12 yu; horns long and crossed. 

 Excretory system : Dorsal canal between ventral canal and nerve at 

 height of the genital canals; genital canals cross dorsally, but uterus 

 crosses ventrally, of the longitudinal canals and nerves. 



Hosts. Pocket Gopher ( } Gcomys bursarius (Shaw, 1800) ), collected 

 by Herbert Osborne at Ames, Iowa. 



Types. Bureau of Animal Industry cestode series No. 1079 desig- 

 nated as type and deposited in the United States National Museum; 

 paratype (1372, part in sections) deposited with type. Technique of 

 types : Corrosive sublimate, alcohol, acid carmine. 



PECTINATA GROUP. 



The European form Cittotcenia pectinata forms, with certain American 

 parasites, a very compact group, but it is difficult to know what rank 

 should be given to this division. Generic rank would be too high, 

 specific rank too low. I propose to include these cestodes in the Pec- 

 tinata group, which I base upon the peculiar cirrus pouch. 



Three species come within this group at present: 



1. Type species C. pectinata, as defined below, p. 188, its chief char- 

 acters being the length of the cirrus pouch, the quadrangular arrange- 

 ment of the testicles, and their extension beyond the ovaries to the 

 lateral canals. 



'Synonymy after Merriam: 1800, Ms bursarins, Shaw; 1815,? M. ludoricianus, 

 Ordway ; *1817, Diplostoma fusca, Rafinesque; 1817, Geomtj8 cinerea, Rafinesque (Mas 

 ftMrartrmsivnamed); 1820, Saccophoru* bursarius, Kuhl ; 1*21, Mas saccalm, Mitcbill; 

 1823, Psetidostoma burmrius, Say; (1822) 1825, Ascomt/s canadeiisis, Lichteufel 1; 1S59> 

 Geomi/sf bnrsariua, Richardson; 1852, Geomys canadensis, LeConte; 1852, G.orcyonen- 

 sis, LeConte. 



C. Hart Merriam, 1895. Monographic Revision of the Pocket Gophers, Family 

 Geomyidje (exclusive of the species of Thomomus), p. 120. North American Fauna, 

 No. 8, Division of Ornithology and Mammalogy, United States Department of Agri- 

 culture. 



