B. Two uteri and two genital pores present; horns of pyriform apparatus well developed; genital ducts pass on the dorsal side of the longitudinal vessels MONIEZIA R. Bl. _a._ Interproglottidal glands[111] arranged in linear series (_planissima_ group) _M. planissima_ S. and H. _M. benedeni_ Mz. _M. neumani_ Mz. _b._ Interproglottidal glands saccular (expansa group) _M. expansa_ Rud. _M. oblongiceps_ S. and H. _M. trigonophora_ S. and H. _c._ Interproglottidal glands absent (_denticulata_ group) _M. denticulata_ Rud. _M. alba_ Perr. C. Uterus single or double, without spore-like egg-sacs; eggs with a single shell; genital pores irregularly alternate; strobila narrow; testes absent from median part of the field STILESIA Raill. _a._ A transverse uterus in middle part of median field; {91} head 2 mm. diameter _S. centripunctata_ Riv. _b._ Two lateral uteri in each segment; head less than 1 mm. in diameter _S. globipunctata_ Riv. III. Scolex almost invariably provided with hooks; genital pores on left border of segment; eggs with three shells but no cornua. Segments broader than long; posterior angles salient. HYMENOLEPIS Weinl. _a._ Scolex with a single series of 24-30 hooks, each 14-18µ long _H. nana_ v. Sieb. _H. murina_ Duj. _b._ Scolex very small, unarmed _H. diminuta_ Rud. IV. Scolex provided with two elongated muscular pits. Body segmented; three genital apertures in middle of ventral surface BOTHRIOCEPHALUS Rud. Body 2-20 metres in length _B. latus_ Brems. _B. cristatus_ Dav. (doubtful species). _B. cordatus_ Leuck. _B. mansoni_ Cobb. (= _B. liguloides_ Leuck.) CLASSIFICATION OF CESTODES.—The following classification, which, so far as the Taeniidae are concerned, follows that employed by Railliet, Blanchard, and most recent writers, includes only a few representative genera:— 1. Fam. CESTODARIIDAE Mont. (MONOZOA Lang). Gen. _Caryophyllaeus_, _Archigetes_, _Gyrocotyle_, _Amphilina_. 2. Fam. BOTHRIOCEPHALIDAE. Sub-Fam. 1. Bothriocephalinae. Gen. _Bothriocephalus_, _Schistocephalus_, _Triaenophorus_ (= _Tricuspidaria_). Sub-Fam. 2. Ligulinae. Gen. _Ligula_. Sub-Fam. 3. Solenophorinae. Gen. _Solenophorus_, _Duthiersia_. Sub-Fam. 4. Diphyllinae. Gen. _Echinobothrium_. 3. Fam. TETRARHYNCHIDAE. Gen. _Tetrarhynchus_. 4. Fam. TETRAPHYLLIDAE. Sub-Fam. 1. Phyllobothrinae. Gen. _Phyllobothrium_, _Echeneibothrium_, etc.