54 



"TERRA NOVA" EXPEDITION. 



measures 0*4 mm. in length. The suckers attain their greatest breadth, 0*2 mm., 

 posteriorly. They have overhanging edges and ear-like prolongations. 



Segments. — The neck is followed by twenty segments. The segments gradually 

 increase in length from behind the head without diminishing in transverse measure- 

 ment. The last segment has a breadth of 0'3mm., and a length of O'lomm. The 

 internal organs begin to develop at the eleventh segment. The genital pores are 

 marginal and on the same side. There is a large thick-walled cloaca. The cirrus 

 is large and muscular. The vagina leads into a wide straight tube. The testes are 

 few in number (twelve in each segment) ; their staining qualities markedly diminish 

 in the last segments. The ovary is situated in the middle line, and near the anterior 

 border of the segment. In front of this is a small, deeply-staining yolk-gland. The 

 cirrus-pouches are external to the excretory canals and are situated marginally, in the 

 middle third of each segment. 



In all the material obtained from Adelie Penguins the strobila had the extra- 

 ordinarily small size above noted. The number of testes is constantly twelve, and the 

 auricular appendages are well developed. 



Three species of Tetrabothrius have been found hitherto in Penguins, viz., T. 

 /hi//)/ ni, Raill., T. eudyptidis, Lonnberg, and T. lutzi, Parona. T. wrighti seems to 

 correspond in many points to the description given by Fuhrmann for T. monticellii. 

 The limited number of testes is especially remarked upon by Fuhrmann as peculiar 

 to this species. T. joubini is reported, however, to have only five to eight testes. 

 The type-material of that species is said to be immature and poorly preserved. 



Fam. DILEPINIDAE. 



Anomotaenia, Cohn, 1900. 

 36. Anomotaenia zederi (Baird). (PI. IV, figs. 23, 24. Text-fig. 11.) 



Taenia zederi, Baird, 1853. 

 Tetrabothrius zederi, Monticelli. 

 Prosthecocotyle zederi, Fuhrmann. 



Host. — Emperor Penguin (Aptenodytes forsteri) ; intestine. 



External Appearance. — The worms measure 4 to 5 cm. in length. The head 

 bears a rostellum and four suckers, and is pointed, while caudad from the suckers 

 there is a well-marked pyriform swelling which subsides after a course of 0*7 cm. 

 to join the segments (PI. IV, fig. 23). 



Head. — The head (text-fig. 11) is pointed, and there is a well-marked rostellum 

 (r) measuring 0*24 mm. by 0'15 mm. transversely. The rostellum is retractile 

 within a well-marked groove on the surface of the head. Its centre, distally, is 

 marked by a small opening, and communicates with a hollow interior which forms a blind 

 sucker situated within the rostellum. There are two series of well-marked hooks (h), 

 nine in each series. The hooks measure 0'09mm. from end to end; 0 ' 04 mm. 

 from the tip there is a well-marked guard. They are 0*01 mm. thick. The four 



