THE CESTOIDEA 



117 



fusion and modification of the bothria, or it may be a rostellar sucker. 

 Cyathocephalus, Kessl. ; C. truncatus, Pall., in fresh -water fish (Fig. 

 XIV.), (see 19). FAMILY 4. LEUCKARTIIDAE. Without apparent bothria. 

 Leuckartia, Moniez, in fish ; Blanchardella, Moniez. FAMILY 5. TRI- 

 AENOPHORIDAE. Body indistinctly segmented, copulatory pore marginal. 

 The bothria are very shallow, but wide ; each is armed distally with two 

 three-pronged hooklets. Triaenophorus, End. ; T. nodulosus, Rud., in 

 pike, and encysted in the tissues of Cyprinoid fishes (Fig. XV.). 



FIG. XV. 



Triaenophorus nodulosiis, 

 Rud., from the intestine of the 

 pike. The left-hand figure re- 

 presents the entire strobila. 

 ( x 2, orig.). a, the scolex ; ft, 

 the series of uterine pores 

 which alone mark the repeti- 

 tion of parts, for there are no 

 distinct proglottids. 



The right-hand upper figure 

 is the scolex. (x 17, orig.). 

 It is viewed rather obliquely, 

 so that a part of one of the 

 hooks of the dorsal surface is 

 shown in addition to the both- 

 rium (a) and the two character- 

 istic hooks of the ventral sur- 

 face. 



Lower figure. The hinder 

 end of the strobila rendered 

 transparent, (x circa 20, orig.). 

 ft, uterine pores ; c, uteri filled 

 with eggs ; d, copulatory pores, 

 irregularly arranged right and 

 left ; e, cirrus ; /, excretory 

 bladder. The rest of the geni- 

 tal organs not presenting any 

 peculiarities are omitted. 



FIG. XIV. 



Cyathocephalus 

 truncatus, Pall., 

 from the intes- 

 tine of Perca 

 fluviatilis. ( x 

 circa 20, after 

 Zschpkke.) a, 

 terminal "suck- 

 er " (see text) ; 

 ft, uterine pore ; 

 d, copulatory 

 pore ; both are 

 alternately dor- 

 sal and ventral. 



FIG. XV. 



Further Remarks on the Dibothridiata. This branch of the 

 Merozoa is more nearly allied to the Monozoa than are the Tetra- 

 bothridiata. The majority of them are parasitic in fresh-water 

 fishes, though the genus Bothriotaenia occurs in birds, and Bothrio- 

 cephalus latus in man. The size of the strobila and the number of 

 proglottids varies considerably, as it does too in the other orders ; 

 the great Bothriocephalus latus, with its hundreds of proglottids, and 

 measuring some 20 feet or more, contrasts with Cyathocephalus, with 

 only some twenty segments, and a length of 20 mm. 



The scolex, though always retaining the two bothria one dorsal, 

 the other ventral exhibits some interesting modifications of the 

 typical structure. The deep, narrow cleft of Bothriocephalus is repre- 



