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Part III. — Tiventy-sixth Annual Report 



and Rata clavata ; while Linton records the same parasite from the Barn- 

 door Skate, Raia laeuis, captured at Woods Hole, Massachusetts. 



Genus Dinobothrium, P. J. van Beneden (1889). 



Dinobothrium septaria, van Beneden. PI. VI., fig. 4. 



1889. Dinobothrium septaria, van Ben., Bull. 1'Acad. Roy. de 

 Belgique, 3me. serie., torn. 17, p. 69, PI. I., 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 j 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. eit., 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 entoure de quatre bothridies, comme dans la plupart des 

 Cestodes de poissons Plagiostomes ; ces bothridies sont placees dos a dos et ne 

 possedent aucune apparence de crochets. Dans 1' etat de conservation actuelle 

 des vers, contractus par 1' alcool, elles ressemblent, a une coquille du genre 

 Septaria. 



Les bothridies sont larges, de forme ovale, attachees par toute la largeur de la 

 base, la face externe concave et couronnees en haut par une saillie qui rappelle 

 jusqu'aun certain point, la charniere de certaines coquilles bivalves. Van Beneden, 

 op. ext., p. 69. 



