38 THE NAUTILUS. 



ing." It is true Lamellidoris aspera occurred in some numbers but 

 the individuals varied much in size, were not markedly gregarious, 

 and no spawn or coition was seen. The species seems to be a fairly 

 common one at most times and according to Alder and Hancock 

 breeds in May, June and July, — if indeed our species be identical. 



None of the species taken are rarities except the var. chocolata 

 (which, however, I have several times seen before) and Cratena 

 veronica, which has not befoi-e been publicly reported since its origi- 

 nal description, but has been taken a few times by Verrill in com- 

 paratively deep water. The present specimen is about three-quarters 

 the size given by Verrill. One may hazard a guess that it will be 

 found to have a shore breeding season sometime in the winter. 



The other species are those we have often with us on the shore in 

 very small numbers. While such of them as are hydroid feeders are 

 almost necessarily to some extent gregarious, I know of no account 

 of anything like a " swarming " of any of them except Ancula 

 cristata} 



There is a certain fascination about the mysterious appearances 

 and disappearances of these beautiful wanderers, and the first student 

 fully to master a nudibranch (or at any rate an Eolid) life-history 

 will have an interesting story to tell. 



A collecting trip like this gives endless opportunity for alleged 

 " observations " on " protective " and "warning," coloration and the 

 like, which would be worth recording if fishes or other enemies looked 

 with human eyes, from air into water, in full daylight, and from on 

 top. Any true advance in this direction must be along the lines of 

 work like Herdman and Ciubb's most interesting experiments,* 



52 Eliot St., Jamaica Plain, February, 1909. 



1 Herdman and Clubb. Third Report upon the Nudibranchiata of the L. M. 

 B. C. District, Proc. and Trans. Liverpool Biol. Soc, iv, 1890, p. 134. "This 

 species {A. cristata) was found * * * in April, 1890, and we took it in extra- 

 ordinary profusion * * * in March, 1890. On one reef of rocks especially, a 

 little way above low-water mark, there must have been many thousands of 

 specimens present. For yards it was impossible to walk without treading on 

 them, and handfuls were readily collected by scraping the specimens together 

 from the mud-covered rocks." It should be remembered that for some reason 

 the British coast supports nudibranch life in a vastly greater abundance of 

 individuals, as well as of species, than ours does. 



"^ Loc. cit., ante, pp. 150-163. 



