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 
Talitrus 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 podoccroides under stones amongst the rocks. The Podo- 
cerides , Pherusa bicuspis , Calliopius grandoculis , and Caprella 
tuberculata are plentiful in the rock-pools, and Corophiurn 
grossipes in the brackish pools near the estuary of the Eden. 
Janira maculosa abounds both in the tidal region and in deep 
water, while Jeer a 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 Sphceroma 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 
