84 Part III—Twenty-siath Annual Report 
and Raia clavata ; while Linton records the same parasite from the Barn- 
door Skate, Rava laevis, captured at Woods Hole, Massachusetts. 
Genus Dinobothrium, P. J. van Beneden (1889). 
Dinobothrium septaria, van Beneden. Pl. VI., fig. 4. 
1889. Dinobothrium septaria, van Ben., Bull. Acad. Roy. de 
Belgique, 3me. série., tom. 17, p. 69, Pl. L., figs. 1-3. 
The specimen represented by the photograph Plate VI., figure 4, is 
from the intestine of a Porbeagle Shark, Lamna cornubica, captured in the 
North Sea in May 1901. The specimen measures about forty-five 
millimetres in length. Each pair of bothria measure about nine milli- 
metres across by about seven millimetres in length. This Cestode is 
readily distinguished by the peculiar form and arrangement of the bothria 
from all other species belonging to this group of parasites. As the species 
does not appear to have been previously recorded from Scottish waters, it 
may be of interest to give the following extract from Prof. van. Beneden’s 
description. The scolex, he says, is surrounded with four bothria, as in 
the majority of the Cestodes of Sharks and Rays; these bothria are 
placed back to back, and possess no appearance of hooks. The worms 
having been preserved in alcohol had become somewhat contracted, and 
the form of the bothria was not unlike a shell of the genus Septaria. 
These bothria are large, of an oval form, and attached by the whole 
length of their base ; the external face is concave and crowned above by a 
projection which in some respects resembles the hinge of certain bivalve 
shells,* 
The specimens recorded by van Beneden measured twenty-five to 
thirty millimeters, and were thus considerably smaller than the specimen 
recorded here. 
Genus Diplobothrium, P. J. van Beneden (1889). 
Diplobothrium simile, van Beneden. PI. VIL, fig. 2. 
1889, Diplobothrium simile, van Ben., op. ctt., p. 70, Pl I, 
figs. 4-8. 
A specimen of a Cestode that appears to belong to this species is 
represented by the photograph, Plate VII., figure 2. This, like the species 
just described, was obtained in the intestine of the same Porbeagle 
Shark in which the other was found. The specimen measured fully 70 
millimeters in length—nearly three inches. 
This Cestode was described by van Beneden at the same time as the 
Dinobothrium, and was also found in a Porbeagle Shark. The Scolex or 
“head” does not at first sight present so remarkable a form as the 
Dinobothrium, but its structure suggests a more or less near relationship 
with species already known to science. A closer examination, however, 
*Le scolex est entouré de quatre bothridies, comme dans la plupart des 
Cestodes de poissons Plagiostomes ; ces bothridies sont placées dos 4 dos et ne 
possédent aucune apparence de crochets. Dans I!’ état de conservation actuelle 
des vers, contractés par Il’ alcool, elles ressemblent, 4 une coquille du genre 
Septaria. 
Les bothridies sont larges, de forme ovale, attachées par toute la largeur de la 
base, la face externe concave et couronnées en haut par une saillie qui rappelle 
jusqu’a un certain point, la charniére de certaines coquilles bivalves. Van Beneden, 
op. cit., p. 69, 
