The Zoologist — August, 1873. 3657 



the bassin of the Garonne at Toulouse, I had the good luck of detecting the 

 singular metamorphoses of this species. In all probability this nymph is 

 the first and only one discovered in this genus up to the present time, as 

 neither Pictet, the founder of the genus (0. anomala), nor Imhoff (0. Rhe- 

 nana), nor Hagen (O. Rhenana, var. palhda), nor my friend Albert Miiller 

 in his different observations on the habits of 0. Rhenana, nor M'Lachlan 

 (0. Trimeniana), nor lastly, even the Rev. A. E. Eaton, in his fine and 

 quite recently published monograph on the Ephemeridae,* mention anything 

 concerning the larval stage (Vetat de ver), or, as it is called in England, 

 " the immature condition of the subaqueous stages of development," of any 

 of the species, the names of which I have enumerated. I intend to publish 

 shortly the complete anatomy of this curious nymph.' " 



With regard to the above notes, Mr. M'Lachlan remarked that it vrould 

 be most desirable to obtain further and more minute particulars respecting 

 Dr. Joly's observations. The information furnished was very vague, and 

 no characters were given of the supposed new species. 



Mr. WoUaston communicated a paper " On the Genera of the Cossonidae," 

 including descriptions of 139 species which had not hitherto been 

 recorded. 



The Secretary read the following remarks, communicated to him in a 

 letter from Mr. Roland Trimen, of Cape Town : — 



"I have lately read with much interest the Rev. R. P. Murray's notes 

 ' On some Variations of Neuration observed in certain Papilionid8e,'t and 

 desire to offer the following remarks thereon. In cases 1, 2, 3 and 4, 

 Mr. Murray does not state whether the anastomosing or coalescing nervures 

 are those of the fore or hind wings ; but in the 1st and 2nd, it is clear, from 

 the mention of Synchloe (Pieris) Mesentina, Cramer, that the fore wings 

 are intended. In this Pieride, however, the junction of the first subcostal 

 nervule with the costal nervure of the fore wings is not an aberration but a 

 constant character of that species, as well as of P. Severina, Cram., and a 

 few aUied species, and (as mentioned by me in Trans. Ent. Soc. 1870, 

 p. 378) has been noticed by both Walleugren and Wallace. 



"I am enabled to supplement case 5, ' P. Clodias' (?Parnassius Clodius, 

 Men.), by a very similar and even more remarkable instance in a male 

 Papilio Merope, Cram., which has just recently come under my notice. As 

 in Mr. Murray's description, the subcostal nervules of the hind wing in this 

 specimen of Merope are connected by a transverse nervule ; but the addi- 

 tional nervule (instead of being incomplete and confined to the right hind 

 wing) is found in both hind wings and thoroughly unites the subcostal 

 nervules. In this manner a perfect additional cell is formed (see a in figure) 



* A. E. Eaton, "A Monograph on the Ephemeridce," in Trans. Ent. Soc. Lond., 

 1871, with six plates. 

 + Proe. Ent. Soc, 1873, pp. xxxiii. — xxxiv. 



