ON A NEW AVIAN CESTODE. 407 
27. On a New Cestode from an Albatross, 
Diomedea irrorata. By H. A. Bayutis, B.A.* 
[Received April 21, 1914; Read May 19, 1914.] 
(Text-figures 1-4.) 
IypeEx. 
CESTODA : Page 
Account of Tetrabothrius strangulatus, sp. n., in Diomedea 
APTORALA TOI, Pe \beeserer tent se eee ee eae oie Se sden co seecens 407 
Among some material presented to the British Museum by the 
Hon. N. C. Rothschild, one tube contained specimens of a small 
cestode collected from Diomedea irrorata Salvin by Dr. H. O. 
Forbes. Locality : Lobos de Tierra Island, Peru. 
Examination of these specimens showed them to belong to the 
genus Tetrabothrius Rudolphi, to which in fact all the Cestodes 
found in this group of birds have been assigned. The species 
appears to be a hitherto undescribed one, for which I propose the 
name Tetrabothrius strangulatus, on account of the sudden con- 
striction observed behind the head, which gives the animal the 
appearance of having had a thread tied round its neck. 
TETRABOTHRIUS STRANGULATUS, sp. n. (Text-figures 1—4.) 
External Features. 
This is a very small form compared with most of the other 
species of the genus. The material is unfortunately in a rather 
fragmentary condition; the longest piece measured 57 mm. 
This fragment contained 222 proglottides, in the first 5 or 6 of 
which there were as yet no traces of genital organs developed. 
The only fragment which includes a head shows about 30 seg- 
ments, in which there are no genital organs, and the length of 
this piece is about 3°5 mm., including the head. At the lowest 
computation, therefore, a complete specimen probably measures 
60 mm. in length and contains about 250 proglottides. The 
maximum width attained is about 0°77 mm. 
As already stated, only one head could be found among the 
specimens. It is of a somewhat oblong shape, flattened dorso- 
ventrally—i, e., in the same direction asthe strobila. At the apex 
it has a flattened area, from which arises a slight conical pro- 
jection. The four suckers are large, placed at the anterior end 
of the scolex, and occupying less than half of its length. They 
have a considerable ear-shaped fleshy expansion antero-laterally, 
and their apertures are irregularly triangular in outline. 
The total length of the head is 0°54 mm., while at its widest 
* Communicated by the SzrcrETARY and published by permission of the Trustees 
of the British Museum. 
