134 MARINE FAUNA OF ST. ANDREWS. 



separated by the presence in considerable numbers of Cymodo- 

 cea truncata and Sphaeroma Prideauxianum in the fissures of 

 rocks between tide-marks, and Dynamene in rock-pools. 

 The characteristic Tanais vitiatus, Paranthura costana, Ncesa 

 hidentata, Mcera grossimana, Chelura terebrans, Conilera cylin- 

 drica, and the large Cymothoa parasitic on the fishes at once 

 distinguish the fauna, of the Channel Islands from that at 

 St. Andrews. The rarity of Orchestia littorea at the latter 

 and its abundance in the tidal region of the Outer Hebrides, 

 and the absence of Sidcator arenarius and its frequent occur- 

 rence in the sand of the western shores of England, are also 

 interesting contrasts. 



Many of the sessile-eyed Crustacea, such as Talitrus locusta, 

 are extremely hardy. Gamniarus locusta is often found in 

 putrid localities, and it survives almost every other marine 

 form in putrid vessels in confinement. The group as a whole 

 is composed of extremely active animals ; and even the most 

 grotesque, such as Caprella tuberculata, are at home in the 

 intricacies of Ceraniium and other finely branched seaweeds. 

 The boring forms (by jaws) are represented by Limnoria 

 Ugnorum ; but its depredations are comparatively insignificant, 

 probably because little wood is employed within water-mark in 

 the construction of the harbour. The perforations of Talitrus, 

 again, abound in the sand, and the looped burrows of Coro- 

 2jhium in the sandy mud of the flats it inhabits. The nest- 

 forming crustaceans are represented hjAmphitlioepodoceroides, 

 Sijjhonoecetus typicus, Podocerus variegatus, and P. falcatus ; 

 while the young of Gammarus locusta are often observed 

 adhering to the abdominal region of the parent. 



The Cirripedes occur abundantly between tide-marks, the 

 most conspicuous being Balanus halanoides, which covers 

 the bare rocky ridges opposite the Castle and other parts. 

 In deep water the various species are attached to shells, 

 stones, crabs, wood, cork, coal, tests of ascidians, and other 

 structures. 



I am indebted to Mr. Spence Bate for the determination of 

 several doubtful forms, and especially to the Rev. A. M. 

 Norman for his courteous assistance in this respect, and in 

 revising the list. Mr. G. S. Brady kindly furnished me with 

 the names of the Ostracoda occurring in shell-debris on the 

 West Sands and other collections. 



