»0 W. BLAXLAND BENHAM. 



much longer. I killed the worms in various fluids ; those in 

 corrosive sublimate showed the last proglottids of about the 

 same length as breadth, whilst in glacial acetic acid they 

 shrank a great deal, and became shorter than broad. The 

 proglottids are a good deal imbricated, the hinder margin of 

 each covering nearly half the succeeding one (in the greater 

 part of the strobila) (fig. 13). The genital pores are alternate, 

 and the side that bears the pore is longer than the other, so 

 that each proglottid is somewhat wedge-shaped. (Here, too, 

 I note a difference in specimens killed differently. Those in 

 acetic acid show this character less than those in corrosive 

 sublimate.) 



Here and there I noted half - proglottids intercalated 

 amongst the others. I believe this phenomenon has been 

 noted in the case of a species of Bothr iocephalus from 

 Japan. 



The eggs, which appear distributed over the entire ripe pro- 

 glottid, are provided with shells only in the last dozen 

 segments or so. Previous to that the blastomeres into which 

 the ovum has segmented are plainly visible, as they readily 

 take the stain; whereas, when once the shell is formed, the 

 stain does not penetrate (in entire worms). 



The onchosphere (fig. 14) measures 003 mm. (this refers 

 to the diameter of the refringent shell only, and does not 

 include the granular envelope ; the eggs, then, and the oncho- 

 sphere are larger than those of D. minuta), and their 

 booklets 0*01 mm. in length. 



The SCO lex is conical, with four large oval suckers, the 

 lower margins of which are often everted and prominent, and 

 appear, consequently, to be mobile. This lower lip does not, 

 however, rise upwards, as in the preceding Cestode, but the 

 cavity of the sucker is directed outwards.^ The shape of the 

 suckers and general appearance of the scolex recall that of 

 certain Selachian Cestodes of the family Tetrabothrid^ ; but 

 the armed retractile rostellum, as well as other anatomical 



^ I have a specimen of tapeworm with a similar scolex from a penguin, but 

 have not yet worked its character out. The shape is peculiar for a Taenia. 



