1'AKASITIC Wolt.MS LKIPER AND ATKINSON. 53 



are more uniform in si/e and shape. The hc;ul is succeeded liy a very short neck, and 

 segmentation be"ius almost at oner. The segments are uniform nearlv the whole \vav 



,~ O 



down the liodv. The genital pores are single and unilateral. 



II,, i, I. The head is lame. It expands from its narrow jmieiion with the neck to 

 its bulbous end. It has four large suckers, whieh are deepl\ hollowed. They open 

 alio\e on its upper surface, and run for some distance along its sides (text-tig. 10). 

 There is a 1'ree horder formed bv the flap making the edge of the sucker. The head 

 measures ir'.i-J mm. from side to side and 1 mm. from liefore backwards. It is roughly 

 sipiare when looked at from in front. Kadi sucker has an outside measurement of 

 0'44 mm. and an inside measurement of (ViM mm. 



Segments. Tnlike the last (Vstode. the uniformity of the shape and si/e of the 

 segments is marked. Thev measure 0'4!> mm. from liefore backwards, and 0'7('i mm. 

 from side to side. The Imnlers are rounded, and they slightly overlap one another, 

 hi a stained specimen the outer portion of the segments 

 remains unstained. The genital openings are unilateral aud 

 occur at the sides, rather upon the ventral surface. The 

 opening measures 0'04 mm. aud is rounded. The cirrus-sac 

 measures ()M4mm. and is also rounded. The vagina is fairly 

 wide. The testes. which number :>0 to 40, are small aud 

 rounded ; thev are contined detiuilelv to the space between the 

 excretorv canals on either side. Thev are also generally 



arranged in three distinct sets- the numlier in the middle atdiemwi : view of the 



, . ,. i- i i -ii i- ^1 ii T anterior extremity of 



set belli''- tar m excess ot that in either of the other two. In 



the scolex. 



front of these and near the cephalic end of the segment are 



the deeply-staining yolk-gland and ovary. The ovary is 0'0(> mm. across and is 

 rounded. The uterus is a simple sae, and the eggs occur late in the hinder segments. 

 Two excretory canals run down either side, internally to the cirrus luit externally to the 

 testes. and are continuous throughout the segments. 



The main differences from the previous Cestode are in the genital openings, the 

 numlier. distribution and arrangement of the testes, the shape of the head and suckers, 

 and the uniformity of the segments in shape and size. 



35. '/', /i-<i/i<>//ii-!/ix ////(/////. Lei p. and Atk. (PI. IV. fig. 2'2.) 



Tetrdbothriui //;/////, Lciper ami Atkinson, Pror. Zi'i'L Sin'.. I'.U-t, [i. -->. 



Strnliil.-i I''- nun. lon.i;, ntinc of tlic segments (-(intaiiiinir i-jr.u's. Head (J-liiiin. in length. Testes 

 ron-lMiitU' twi-he. Auricular :i]iiiencl:iL'es nf suckers well developed. 



//>-!. A few of these minute Cestodes were obtained from the -lit of the Adelie 



Penguin (/'//t/i'xi-! /!.* ml, I'm,), a species which is usually peculiarly free from parasites of 

 anv kind. 



1 1,, nl. The short neck is surmounted liv a larue head with four suckers and 

 a peculiar rounded armature. There is no rostellum. nor do hooks occur. The head 



K -2 



