10 Mr John Goodsir on Gymnorynchus horridus, 



the last edition of Lamarck's invertebrate animals, has defined 

 the genus thus : — body depressed, continuous, or without arti- 

 culations, composed of three parts ; one median, subglobose, 

 prolonged backwards into a very long tail, and forwards into 

 a wrinkled neck ; the cephalic bulging, provided with two bi- 

 partite suckers and four papillose tentacula. 



When dissecting the sun-fish, which formed the subject of a 

 former communication to the Society, I found in the liver a 

 number of entozoa which presented a very curious appearance. 

 They were cylindrical, very much elongated, coiled and 

 twisted on the surface and in the substance of the organ, one 

 of their extremities subglobose, and situate immediately 

 under the peritoneum, the other tapering to a fine point. 

 They adhered to the parenchyma of the organ by cellular 

 tissue, and occasionally where one coil lay over the other, the 

 two adhered. Their colour was cream-white, so that they con- 

 trasted strongly with the deep brown of the liver. 



On removing one of them, and making a longitudinal inci- 

 sion, I found that it was not a worm, but an elongated sac or 

 cyst containing a worm, wdiich, w^hen withdrawn, was found 

 to be alive, although the fish had been a week dead. When 

 placed in lukewarm w^ater, it pushed out its head and neck 

 from the cervical receptacle, protruded the four-armed tenta- 

 cula, and continued in lively motion for some hours. The 

 globose receptacle, with the head and neck of the worm, were 

 lodged in the bulbous extremity of the cyst, but the tail did 

 not extend into the attenuated extremity. 



I had no difficulty in referring the worm to the genus Gym- 

 norynchus. I may remark, however, that it presented one 

 character not included in the definition of this genus. It ex- 

 hibited, when gently compressed between two plates of glass, 

 distant, but distinct articulations. From an examination of 

 Bremser's drawing, and a consideration of the relations of the 

 genus, I strongly suspect that the old species is also articulated, 

 and that such a conformation must be considered as a charac- 

 ter of this cestoid genus. My specimens present a character, 

 which appears to be sufficient to distinguish them as a ne^v 

 species. They have a separate circle of large recurved hooks 

 on the tentacula, an arrangement not to be seen in Bremser's 

 figure of Gynmorynchns reptans* 



