NEW AVIAN TAPEWORM. 195 



point of view. The species are Idiogenes otidis, Chapmannia lapica, 

 Hyinenolejns lullosa, H. tetrads^ and H. atnbigicus. There is no 

 doubt that the species which forms the subject of the present 

 communication to the Society is none of these ; nor can I reconcile 

 its characters vvitli those of any other genus of Tapeworms of the 

 group Tetracotylea (of which group it is undoubtedly a member) 

 which have been described up to the present. I shall, however, 

 defer the attempt to fix its systematic position until I have 

 described its anatomical characters. 



I have examined four complete specimens of this worm, besides 

 some fragments which may or may not have belonged to those 

 specimens. The largest was about 3 inches in length, and the 

 greatest diameter of the posterior segments was 4 mm. The 

 diameter of the body gradually increases f}om the head up to the 

 point of greatest diameter, and then remains the same ; there is 

 not, as in so many tapeworms, a narrow anterior region of the 

 body, which suddenly widens within the limits of two or three 

 proglottids. The general shape is thus much like that of certain 

 species of Bertiella, for example of B. cercopitheci *. There is, 

 however, no further resemblance between the present genus and 

 Bertiella in external form. The worm is white in colour ; but 

 there is some black pigment in the head behind the suckers, and 

 the ripe proglottids are of a brick-red hue. 



The scolex of this new worm — for which I propose the generic 

 and specific names of Otiditcvnia eupodotidis, as indicative of its 

 habitat — is not pai'ticularly small nor, on the other hand, con- 

 spicuous by its large size. I have not found the least trace of 

 hooks anywhere on the suckers. The head seems be completely 

 unarmed as to the suckers, but the rostellum has hooks. 



The four suckers are, as is so often the case, extremely mobile, 

 and can be protruded a long way from the head as cylindrical 

 processes. In this case they look rather forwards than outwards. 

 When retracted and in a normal condition the suckei's look out- 

 wards and slightly upwards. When fully protruded the suckers 

 give to the head of this worm an appearance very like that of the 

 genus of Tetraphyllidea, Ci/lindrophotms f. 



I have investigated the structure of the rostellum and lateral 

 suckers by transverse sections through the head. There is nothing 

 remarkable about the structure of the suckei^s. The rostellum, 

 however, demands some consideration. When the worm is ex- 

 amined with a lens or with a low power only of the microscope, 

 the appearance presented is that of a median sucker such as occurs 

 sometimes, though, as it is stated by Kiichenmeister J, not always, 

 in Tcenia saginata. The hooks are, in fact, so minute that I was 

 unable to detect them when studying the worm in that fashion. 

 Nor can they be detected save with high-powered lenses. The 

 varying condition of the retraction of the median sucker, or rather 



* See Beddard, P. Z. S. 1911, p. 640, text-fig. 151. 



t Bronn's ' Klassen u. Ordnungeu des Thieireichs,' Bd. iv. Taf. 42. fig. 14. 



X ' Die Parasiten des Menschen,' Leipsic 1881, p. 140, pi. ii. tig. 3. 



13* 



