662 JOTTINGS FROM SYDNEY UNIVERSITY BIOLOGICAL LABORATORY, 



anterior end ; this extremity would be pushed out with great 

 rapidity and the whole of the anterior part of the body would 

 become stretched and narrow ending in front in a point. Then 

 the anterior end would be drawn back and that part of the body 

 greatly contracted and thickened — the extreme anterior end 

 sometimes becoming involuted within the part immediately 

 following it. 



The body is divided into a number of narrow segments which 

 are very sharply defined in front, except when the l)ody is stretched 

 to its utmost, but becomes less marked behind. These are not all 

 perfectly regular, but their length is in general less than a third 

 of the breadth of the body. A well-marked notch, most distinct 

 when the animal is contracted, is found at the anterior end. On 

 no part of the body is there any opening to be found, and there 

 is no vestige of hooks or suckers. 



At first I was greatly puzzled as to the relationships of this 

 remarkable parasite, but an examination of sections showed at 

 once that I had to do with one of the so-called " parenchymatous" 

 worms ; and the absence of an alimentary canal proved that it was 

 among the Cestodes and not among the Trematodes that 1 had to 

 look for its nearest relatives. That it must be a scolex was 

 evident from the situation in wliich it was found, as well as from 

 the absence of reproductive organs. 



Only three genera of the Cestodes are known to have solid, 

 elongated scolices, viz., Tetrarhynclius, Schistocephalus and Ligida. 

 The movements of the anterior end of the scolex of Tetrarliynchus 

 gigas from the muscles of OrfJiagoriscns mola as described by Van 

 Beneden resemble closely those of the parasite of Hyla — " Cette 

 partie du corps s'etend, se raccourcit, s'etrangle, se recourbe, 

 tantot a droite, tantot a gauche, et semble chercher avec anxiete 

 un tissu a perforer."* But the form is cylindrical, or nearly so, 

 and there is an entire absence of segmentation. 



* " Sur les vers parasites du poisson-lune ( Orthagoriscus molaj et le 

 Cecrops Latreillii qui vit sur ses branchies." Bulletin de I'Acad6mie Koyale 

 <le Belgique, Tome XXII. 



