CRUSTACEA. 133 



Series II. ARTHROPODA. 



Class CRUSTACEA. 



The sessile-eyed Crustacea of St. Andrews are tolerably 

 numerous both in species and individuals. Between tide- 

 marks the most conspicuous (as usual) are the swarms of 

 Talttrus locusta which speedily reduce dead fish and other 

 animals to skeletons at high-water mark and considerably be- 

 yond it, and the multitudes of Gammarus locusta and Amphi- 

 thoe podoceroides under stones amongst the rocks. The Podo- 

 cerides, Pherusa bicuspis, Calliopius grandoculis, and Caprella 

 tuberculata are plentiful in the rock-pools, and Corophium 

 grossipes in the brackish pools near the estuary of the Eden. 

 Janira maculosa abounds both in the tidal region and in deep 

 water, while Josra Nordmanni occurs in numbers under stones 

 near high-water mark. In the laminarian region one of the 

 most abundant, perhaps, is Atylus Swammerdami, which con- 

 gregates in swarms on the loose seaweeds. Siphonoecetus 

 typicus is common amongst shell-gravel, and Eurydice pulchra 

 on the surface of the sea as well as in rock-pools in autumn. 

 Many of the rarer forms occur in the deeper water in con- 

 siderable numbers ; but the distribution of the group in 

 British seas is still involved in considerable obscurity; and 

 at present it will suffice to observe that two of the most plen- 

 tiful in this region are Ampelisca Belliana, Bate, and the 

 new Calliopius bidentatus, Norman. The former is likewise 

 common on the beach after storms and in the stomachs of 

 fishes ; and the latter ranges to the laminarian zone. 



Compared with the Zetlandic area, the absence at St. 

 Andrews of such forms as Acanthonotus Owenii, Dexamine 

 vedlomensisj Cymodocea truncata, and Sphmroma Prideauxia- 

 num in the laminarian region strikes even a superficial observer 

 of the group ; while the large number of rare and new spe- 

 cies which were met with during the frequent dredgings of 

 Dr. Gwyn Jeffreys and the Rev. A. M. Norman still further 

 heightens the contrast. The southern region, again, is boldly 



