of the Fisher 1/ Board for Scotland. 77 



Sebastes norvegicus does not appear to be a very rare fish in the waters 

 round the more northerly parts of the Scottish coasts, bat the examples 

 from which the specimens of (Jhondr acanthus here recorded were obtained 

 were captured in the vicinity of Iceland. 



PLATYHELMINTHA. 

 Trematoda. 

 Genus Octobothrium, Leuckart (1828). 

 Octobothrium Sybillce* sp. n. PI. IV., fig. 12. 



This is a small species, being only about two and a half millimeters in 

 length. Like some others of the same genus, it is flat, elongated, and 

 narrow. The anterior extremity is about half the width of the middle 

 portion of the body, and is narrowly rounded in front. There are two 

 small submarginal suckers on the ventral aspect, one being on each side 

 and a little in front of the mouth, which is in the median line. From 

 the anterior end the width gradually increases towards the middle, then 

 tapers slightly posteriorly. The posterior end expands and assumes a 

 fan-like outline, but with the apex truncated. Round each of the two 

 lateral margins of t"he fan-like expansion are four prominent " suckers." 

 Each sucker appears to be divided into two subequal portions, as shown 

 in the drawing (fig. 12). 



A single specimen of this species of Trematode was obtained on the 

 gills of a Trout, Salmo fario, Linn., captured by Dr. H. C. Williamson in 

 Loch Tay, Perthshire, in August 1901. 



Genus Distomum. 

 Distomum cestoides, Ed. van Beneden. PL V., fig. 12 ; PL VII., figs. 3-5. 



1870. Distoma cestoides, P. J. van Ben. Les Poissons des cotes 

 de Belgique, p. 17, PL IV., fig. 9. 



P. J. van Beneden, in the work referred to above, mentions the occur- 

 rence of a large trematode in the sesophagus of Raia batis captured on the 

 coast of Belgium, which he records under the name of Distoma cestoides. 

 A few specimens, comprising adults and young, of what appear to be the 

 same species of the Trematoda have been observed in large Raia batis 

 brought to the Fish Market at Aberdeen. One of the adult specimens is 

 represented by the Photograph Plate VII., fig. 3. It measures nearly two 

 inches in length and between five and six millimeters in diameter. The 

 specimen is cylindrical in form, and the ventral sucker is situated near the 

 terminal one. One or two of the other specimens were even longer than 

 that photographed, the largest measuring about two and three-quarter 

 inches in length. 



It was observed that one or two of the larger specimens were deeply 

 pigmented immediately posterior to the ventral sucker; these when 

 dissected were found to contain ova in abundance ; the ova were of a 

 dark chocolate-brown colour, oval in form, and measured about 

 •1147 x *0806 mm. (PL V., fig. 12). Besides the mature specimens, 

 others varying in size and evidently immature were also observed, the 

 smallest of which being only six to eight millimeters long (PL VII. 

 fig. 4). 



* Sybilla, Queen of Alexander I. of Scotland and daughter of Henry I. of 

 England, is buried in a small island near the east end of Loch Tay. The Highland 

 Tay, by Hugh Macmillan, p. 80. 



