ZOOPHYTES. 35 



Class ACTINOZOA. 



Though the total number of species of this class at St. 

 Andi-ews is small, many occur in great abundance, and espe- 

 cially such cosmopolitan forms as Actinia mesemhryantJiemum, 

 Tealia crassicornis, and Actinohha diantlius. The frequent 

 occurrence of Sagartia troglodytes, again, at St. Andrews, 

 distinguishes it from the shores of the extreme south, as at 

 Guernsey. We have not, moreover, the fine AntJiea ceretis 

 of the west and south, which, for instance, in the quiet creeks 

 of the Outer Hebrides studs the stems and blades of the 

 tangles at the border of the littoral zone, the beautiful greenish 

 puii^le tentacles gently waving with every swell of the tide ; 

 neither is the gaudily tinted Sagartia parasitica, so character- 

 istic of some of our southern shores, to be found between tide- 

 marks, nor Adamsia palliata in deep water. Gorynactis, the 

 stony corals, Zoantlms, and the northern free-swimming 

 Aracknactis albida are entirely absent. The places of these 

 are filled by swarms of the common forms above mentioned, 

 and by some of the rarer types, e. g. Edwardsia, Cerianthus, 

 and Peachia, which seem to be characteristic of sandy beaches. 

 A remarkable example * of the latter turned inside out occurs 

 in my collection. It was mistaken for a curious polyp witli 

 beautifully ai-ranged longitudinal and transverse muscular 

 bundles, and was found inserted in a tunnel in the sand in 

 this condition in Cobo Bay, Guernsey. It is simply a large 

 Peachia everted. 



Amongst the Alcyonarians the phosphorescent Pennatula 

 occurs in great beauty, and replaces the Pavonaria of the west, 

 while with Virgularia it also affords a diagnostic mark from 

 the south. The fine Gorgoniada of the latter region, again, 

 have no representatives at St. Andrews. 



* I am indebted to Dr. Cooper, of St. Peter Port, for the speci- 

 men. 



f2 



