32 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



living animal and of observing the condition of the cnida 

 or stinging cells. We also found Galvina picta again, and 

 Mr. Walker has sent us specimens dredged at Colwyn Bay 

 during the same month. There can be no doubt that 

 this species is becoming more abundant in the neighbour- 

 hood. 



We were much impressed on both the February 

 and March visits to Hilbre with the effective protection 

 afforded io Doris Ulamellata by its rich yellow and brown 

 tints which, although rendering it conspicuous in a 

 white dish or a vessel of clear water, harmonize com- 

 pletely with the animal's natural surroundings, the dark 

 purple-brown rocks spotted with patches of adhering 

 mud, sand, small Algse and Zoophytes. A reef of rock 

 which we were exploring on the March visit had a num- 

 ber of specimens of this Nudibranch scattered over it which 

 were not at first noticed because of the perfect manner in 

 which their colours blended with those of the environment. 



Ancula cristata was again present in extraordinary pro- 

 fusion at Hilbre in March. On one reef of rocks a little 

 way above low water mark, there must have been many 

 thousands of specimens present. For yards it was im- 

 possible to walk without treading on them, and handfuls 

 were readily collected by scraping the specimens together 

 from the mud-covered rocks. Many of these we brought 

 to Liverpool alive and used for the experiments with fishes 

 in the Museum Aquarium, which were described in our 

 Third Eeport on the Nudibranchiata, and in "Nature" for 

 26th June, 1890. This Nudibranch anchors itself to the rock 

 by a string of mucus attached to its tapering tail, and this 

 habit enables it to live as it does on exposed rocks in the 

 wash of the tide. I have several times watched specimens 

 of Ancula in a few inches of water when there was a strong 

 tide running past the rocks and waves dashing on them, 



