Miscellaneous. 445 



ill which he shows that the animal is provided with a rudimentary 

 fin on each side ot" the terminal gland, which had been rubbed oU' or 

 otherwise destroyed, so that their base appears to form part of the 

 gland itself in Mr. Cuming's specimen. 



The j)aper above referred tu, being ])ublishcd in a work cliiefly 

 devoted to anatomy and medicine, had escaped my knowledge. 



I will shortly send you a copy of the figures, with some other 

 particulars, for the purpose of completing the history of this interest- 

 ing genus. Believe me, my dear Sir, yours very truly, 



15th May, 1815. J. E. Guay. 



[Tlie observations of M. de Blalnvillc were noticed by Mr. Owen 

 in one of his Hunterian Lectures, pul)lished in 1843, of wliich the 

 following is an extract : — 



" The genus in which the shell most nearly resembles that of the 

 tctrabranchiate Ccj)halu2)ods, belongs to the Spirula. A few muti- 

 lated sj)eciuien3 which had reached this country during this present 

 century had demonstrated it to be an internal shell, and the more 

 perfect s2K>ciraen dissected by 'SI. de Blainville in 1839, j)roved it to 

 have the characteristic organization of the Dibranchiate order, and 

 to possess, as Peron had indicated, the eight short arms and the two 

 long tentacula of the Decai^odous tribe." — Ed.] 



ON THE DEVELOrjIENT OF DORIS. BY C. W. PEACH*. 



[With a Plate.] 



Goran Haven, Cornwall, April 1845. 

 Having in the early part of 1844 noticed white-spotted jelly-like 

 films suspended from the rocks in the cove near my residence, my 

 curiosity was excited to know what they were. On the 18th of 

 January of that year, I observed that they were more plentiful than 

 I ever before saw them, and on rocks considerably nearer high water 

 mark. I also found a great number of a small kind of Doris on tlie 

 same rock ; not having seen them there before, I began to suspect that 

 in all probability they had something to do with the above-mentioned 

 films. 1 took several of them and placed them in a vessel containing 

 sea- water ; the next morning I found that a pair of them had fixed 

 their ova to the side of the dish, in every respect agreeing with those 

 found on the rock, thus confirming my suspicions. They shed their 

 ova in pairs. I took also with the animal several pieces of their ova 

 from the rock and kept them in a glass of sea- water, and on the 5th of 

 February found that the young had come forth in thousands. I just 

 mention, that no mistake might be made, that I always filtered the 

 water I sui)plied the ova Avith through three or four folds of linen ; and 

 moreover, 1 saw the young moving about in the ova long before they 

 came out, and also observed others there some time after their elder 

 brethren had left. These young are contained in a Nautilus-like 

 shell so small (indeed a mere speck), as not to be made out as such 

 by the unassisted eye. The animal is furnished with two arms of a 



* Head at tlie last Annual Meeting of the Royal Institution of Cornwall. 



