ALDERIA MODESTA. 



characteristic of the eggs of the nudibranchiate gasteropods, a fact which is of itself sufficient 

 to prove that this strange semi-marine and even semi-aqueous habitat was quite natural to our 

 little nudibranch. Their bodies were enveloped in an exceedingly abundant mucous secretion, 

 which was poured out more copiously than I recollect to have witnessed in almost any other 

 gasteropoda and which is perhaps in some way connected with their singular, almost amphibious 

 habits." This species was again met with, in the same locality, in September, 1846, and Dr. 

 Allman kindly forwarded specimens to us, which, though they unfortunately did not reach 

 us alive, were sufficiently fresh to enable us to make drawings of them in their natural colours. 

 The Alderia has since been met with in Loughor Marsh, near Swansea, where it was found 

 by Mr. Moggridge and Mr. C. Spence Bate in 1850. The latter gentleman states* that it was 

 "first detected by Mr. Moggridge in the month of May, when it was on confervas floating in 

 the centre of a ditch made brackish by the occasional admission of sea-water. Later in the 

 year, fructification having been completed, we found the animals crawling on the sides of 

 the bank." From this locality we have been also kindly favoured with specimens. 



The spawn of this little animal is very peculiar. The gelatinous envelope is rather broad 

 and irregularly semicircular, but the chain of ova within is convoluted in a very curious 

 manner, forming alternate loops on each side. This arrangement may be more readily 

 understood by a reference to our figures than by description. 



The species extends to Norway, where it was discovered by Professor Loven. 



Our figures were taken from dead specimens in a fresh state, assisted by the drawings of 

 M. Loven and Mr. C. Spence Bate. 



Figs. 1 , 2. Side and back views of Alderia modesta. 



3. Two of the branchial papillae, much enlarged. 



4. Spawn. 



5. A portion of the same, more highly magnified. 



* Notes on the Fauna of Swansea, p. 6. 



