Notices of Irish Entozoa. 



573 



Tetrarhynchus solidus. 



Tetr. capite truncato, utrinque botlirio angusto, corpore antice magno- 

 pere incrassato, cauda obtusa rotundata. — J. L. D. 



On the same day on which I found the last species {Tel. 

 grossus), I obtained from the peritoneal coat of another salmon 

 two specimens of a Tetrarhynchus which has not yet, I be- 

 lieve, been described.* The first of these was included in 

 the loose peritoneal web which connects the pyloric caeca to 

 each other, and the second was involved in the mesentery, 

 being also surrounded by a peritoneal covering. On the 25th 

 of July I found a third specimen in the mesentery of a salmon, 

 and since that a fourth, involved in the peritoneal coat of the 

 rectum of the same fish. 



Description. — White, with a scarcely perceptible tinge of rose colour ; 

 length an inch and a quarter ; head truncated, with a linear bothrium a 

 line and a half long on each of the two flat surfaces, and with a raised 

 fleshy margin ; proboscides four, very distinct, cylindrical, rounded at the 

 ends, and armed with numerous transparent, rigid hooks ; body thick an- 

 teriorly, but contracting gradually to a little below the middle, from which 

 it continues of equal diameter to the tail end, which is slightly thickened, 

 rounded at the point and very obtuse. 



29 ^Ev^/ik ^k&*r 7 a > Tetrarhynchus solid - 



us, a straight speci- 

 men. 

 b, Ditto, a crooked spe- 

 cimen attached to a 

 portion of the rectum 

 of a salmon. 

 e, Part of the head 

 magnified. 



d, The torn proboscides. 



e, Bothrium, its edges 

 separated artificially 

 from each other in a 

 specimen preserved 

 in alcohol. 



/, Front view of the 

 points of the probos- 

 cides. 



Tetrarhynchus solidus. Drum. 



The whole animal is cylindrical and sub-depressed. Two 

 of the specimens were nearly straight, (Jig. 29, «), the others 

 had each two very abrupt geniculate bends, [Jig. 29, b) 9 and 

 so very firm was the substance of the worm that these could 



* It is impossible, in a provincial town like Belfast, to have access to all 

 the books one could wish, especially to foreign works; but should I on any 

 occasion bring forward a species as new, and find afterwards that it had al- 

 ready been described, I will of course, at the earliest opportunity, rectify 

 the mistake. 



3 l 2 



