PROCEEDINGS OF TJfj: NATIOXAL MUSEUM. 147 



that they can scarcely be recognized, it can hardly be expected that the 

 larvie can be determined with certainty. The work by Mrazek, Moniez, 

 Ilamann, von Linstow, and others in describing these larval forms has 

 been most valuable ; but authors have, I believe, generalized too much 

 upon these observations. 1 



Acknowledgments. I am indebted to the following gentlemen for fur- 

 nishing me with specimens for study in preparing this revision : 



Prof. Eaphael Blanchard, of Paris: A portion of Baird's type of 

 Tcenia goezei; specimens of Anoplocephala wimerosa and Cittotcenia 

 leuckarti. Dr. Gustav Brandes, of Halle: Original cotypes of Eiehm's 

 Dipylidium pectinatum, D. leuckarti, and D. latissimum. Geheimrath 

 Karl Mobius and Dr. A. Collin, of Berlin: Fragment of Kudolphi's 

 Tcenia pectinata. Prof. Herbert Osborn, of Ames, Iowa: Specimens of 

 Cittotamia prcecoquis. Prof. M. J. Elrod, of Bloomington, Illinois : Speci- 

 mens of Bertia americana. Mr. J. H. Tallichet, of Austin, Texas : Speci- 

 mens of Davainea salmoni and Cittotcenia variabilis. Dr. A. K. Fisher, 

 Division of Mammalogy and Ornithology, United States Department 

 of Agriculture: Specimens of Davainea rctractilis. Mr. Eobert A. 

 Mills, of Chuluota, Florida: Specimens of Cittotcenia variabilis imbri~ 

 cata. Dr. Austin Peters, of Boston, Massachusetts: Specimens of C. 

 variabilis, 



The other material 2 used belonged to collection of Bureau of Animal 

 Industry (collected by Curtice, Hassall, Stiles) 5 collection of the United 

 States National Museum; collection of Leidy (University of Pennsyl- 

 vania), and collection of Stiles (United States National Museum). 



Although this article treats primarily of leporine cestodes, it has 

 been found necessary to include several forms from other hosts for 

 comparison. 



To my assistant, Albert Hassall, I am indebted for the entire technique 

 connected with the specimens used, and also for the preparation of the 

 bibliography, and to Mr. W. S. D. Haines, artist of the Bureau of Ani- 

 mal Industry, Department of Agriculture, for preparing the plates. 



Unfortunately much of the material at my disposal was poorly 



1 For a detailed discussion of this subject cf. Stiles : Keport upon the Present Knowl- 

 edge of the Tapeworms of Poultry, Bull. 12, Bureau of Animal Industry, U. S. Depart- 

 ment of Agriculture, 1896, pp. 7-73, pis. i-xxi. 



2 Since issuing my preliminary note on this group, I have received the following 

 specimens from the gentlemen mentioned : 



Prof. A. Moniez, of Lille: His entire collection of auoplocephaline cestodes, 

 including the type specimen of Tcenia wimerosa and undetermined specimens of 

 Cittoicenia denticulata and C. pectinata. Geheimrath Rudolf Leuckart, of Leipzig: 

 cotypes of Riehm's Tcenia rhopalocepliala and T. rhopaliocephala and one of Meyner's 

 originals of Tcenia (Bertia) mucronata. Dr. Victor A. Norgaard, of Alice, Texas: 

 Specimens of Davainea salmoni. Dr. O. A r on Linstow, of Gottingen : Specimen of 

 Cittotcenia pectinata. Dr. von Marenzeller, of Vienna : Several of Riehm's cotypes. 

 Dr. Collin, of Berlin : Rudolphi's cotypes of Tcenia denticulata. 



The manuscript of this article was delayed in order that these specimens could 

 be studied and the results incorporated in the revision. 



