1888.] ON TiBK PblSON-ORIGANS OF TRACHINiaS. 3^9 



and the Ceylon species. I suppose S, octona will soon get down 

 here ; I am on the watch for it." 



Prof. Bell exhibited and made remarks on a specimen of Cerian- 

 thus membranaceus in its tube ; this fine example had been obtained 

 by Mr. John Murray at a depth of 71 fathoms in Loch Etive. 



Mr, Tegetmeier exhibited and made remarks on the feet of an 

 Australian Rabbit, supposed to have acquired arboreal habits, and 

 made some observations on the change of habits of this Rodent 

 since its introduction into Australia. 



Mr. J. B. Sutton, F.Z.S., read a paper on some abnormalities 

 occurring among animals recently living in the Society's Gardens. 



The following papers were read : — 



1. On the Poison-Organs of Trachinus. By W. Newton 

 ParkeRj F.Z.S., Professor of Biology in the University- 

 College of S. Wales and Monmouthshire. 



[Received June 2, 1888.] 

 (Plate XVII.) 



Although it is well recognized that the British "Weevers (Trachinus 

 draco and T. vipera) are poisonous, most ichthyologists express doubt 

 as to the existence of any specific glands in connexion with the 

 stinging-apparatus, some even denying altogether the presence of 

 such glands. 



Before passing on to a description of my own observations, I will 

 briefly refer to those of former investigators whose works I have had 

 an opportunity of consulting. It must, however, be noted first that 

 in both species of Weever the anterior dorsal fin is provided with 

 five or six strong and grooved spines, the second and third of which 

 are the longest ; and a still larger spine is present upon the opercular 

 bone, extending backwards, and projecting freely for a short distance 

 posteriorly. All these spines are enclosed in a sheath of connective 

 tissue, and their apices are sharply pointed ; in transverse section 

 they have somewhat the form of the letter T, the base of the T 

 being anterior in the case of the dorsal, external in the case of the 

 opercular spines. 



In 1841, Allman (1)^ accurately described and figured the oper- 

 cular spine of T. vipera. But he could detect no gland, " only a 

 small pulpy mass in each of the conical cavities," at the base of the 

 spine, which he thought might possibly be of a glandular nature, 



1 The numbers in brackets refer to the list of works at the end of this paper. 



25* 



