194 TAPEWORMS OF HARES AND RABBITS STILES. VOL.XIX. 



1884, Subg. Microtcenia, 1 SEDGWICK, in GLAUS & SEDGWICK, Elementary Text-book 



of Zoology, I, p. 336. 



1886, Cystoidei, K. LEUCKART, Die Parasiten des Menschen, 2d ed., I, p. 825. 

 1886, Group Cystoidotcenice, RAILLIET, filaments de Zool. m6d. et agric., p. 253. 

 1896, DipyUduncc, EAILLIET, Recueil de Me~d. vdt., 8 ser., Ill, 5, p. 159. STILES, Bull. 



12, Bureau of Animal Industry, U. S. Dept. Agric., 1896, p. 28. 



Diagnosis. Taeniidse with rostellum which is generally armed ; geni- 

 tal pores lateral (marginal), single or double; eggs with thin transparent 

 shells, frequently arranged in egg sacs, in some cases scattered through 

 the segments ; larval stage a cysticercoid ; adults in birds and mam- 

 mals. 



Type. Dipylidium, E. Leuckart, 1863. 



Genus DAVAINEA, R. Blanchard & A. Railliet, 1891. 



1891, Davainea, R. BLANCHARD & RAILLIET, Me~m. Soc. zool. France, IV, p. 428. 



Type, Tcenia proglottina, Davaine, 1860. 

 ?1893, Chapmania, MONTICELLI, Naturalista Siciliano, XII (7-8-9), pp. 16-19. Type, 



Tcenia ar</e/ina,-Zschokke, 1888. 



Diagnosis. Dipylidiinre of small or medium size. Head surmounted 

 by a rostellum or hollowed by a depression, but armed in either case 

 with a double row of numerous small hooks of special form (prong and 

 dorsal root short, ventral root very long, giving to the hooks the form 

 of a hammer). Suckers bordered with several rows of small hooks 

 which may be instable or persistent. Genital pores unilateral or irreg- 

 ularly alternate; in the former case the ova are generally arranged in 

 egg capsules; in some species the ovary develops into uterus; eggs may 

 also be isolated, scattered through the parenchyma. 



Type. Davainea proglottina (Davaine, 1860), E. Blanchard, 1893. 



Habitat. Adults in intestine of birds and mammals; cysticercoids, 

 generally in arthropods and mollusks. 



This genus is found chiefly in birds, but two species have been 

 recorded in mammals, besides the two species here given for Lepus. 

 The diagnoses of the two other forms, which are introduced for com- 

 parison, read as follows : 



DAVAINEA MADAGASCARIENSIS (Davaine, 1870), R. Blanchard, 1891. 



1870, Tcenia madagascariensis, DAA^AINE, M6m. Soc. Biol. Paris, 5 ser., I (1869), 1870, 



pp. 233-240, pi. I 

 1891, Davainea madagascariensis (DAVAINE, 1870), R. BLANCHARD, Me"m. Soc. zool. 



France, IV, pp. 429, 438. 



Diagnosis. Davainea madagascariensis (Davaine, 1870), E. Blanch- 

 ard, 1891. Strobila attains 250 to 300 mm. in length, and is formed of 

 500 to 600 trapezoidal segments which are broader than long. Head 



: The subgenus Microtcenia of the genus Tcenia contains the species Tcenia cncu- 

 merina, T. elliptica, T. nana, and T. flavo-punctata, and is thus antedated by the genera 

 Dipylidium, Leuckart, 1863, Diplacantlms, Weinland, 1858 (nee L. Agassiz), and 

 Hymenolepis, Weinland, 1858, but the type has never been proposed. In order to 

 derinitely dispose of the genus I propose Tcenia cucumerina (= Tcenia canina} as type, 

 thus making Microtcenia a synonym of Dipylidium. 



