306 On the Littoral Fauna of the Anglo-Norman Islands. 



Griffithsiwj and all the types wliicli I captured with the dredge 

 at Jersey. Certain forms of Decapods, such as Pirimela den- 

 ticulata^ Xantho fiorida, and X. rivulosa, are common at 

 Guernsey. But in general the fauna of the higher Crustacea 

 is not very rich, especially in the nortli of the island. Scijl- 

 larus arctus, Roera., is frequently brought in by the fisher- 

 men, who dredge it off the island. 



As regards the Isopoda and Amphipoda, they are absolutely 

 identical with those of Jersey. Certain species, such as 

 Paranthura Costana, Apseudes talpa^ Tanais vi'itatus, and 

 LeptocJielia Edioardsii^ are commoner at the Grand Havre and 

 in Belgrave and Rocquaine Bays than at Jersey. 



Mollusc A. 



A considerable number of species recorded by M. Duprey 

 at Jersey have not been met with by me at Guernsey. But 

 the results obtained by a few weeks of researches must not be 

 compared with those obtained by M. Duprey by a long inves- 

 tigation. In the list of animals which concludes this memoir 

 I have indicated some species which he did not find at Jersey 

 and which I have met with in Guernsey in the north of the 

 island. 



As in Jersey, the Nudibranchs are represented by Doris 

 Jlammea^ Aid., D. tuherculato, A. & H., D. Johnstoni, A. & 

 H., Eolis Cuvieri, Lam., Triopa claviger^ Miill., and Pleuro- 

 branchus inemhranaceus, Mont., species which are all common 

 enough in the Zostera-mendows. 



In the north of the island of Guernsey there are two pools 

 of brackish water, one situated near the church of Vale, in a 

 private property, the other to the west of the Grand Havre, 

 near the road which skirts the west side of that bay and leads 

 towards the Pointe Rousse. Near St. Sampson, in the neigh- 

 bourhood of the old castle of Vale, there is also a small stream 

 of brackish water, in which we find only Paliemon varianSj 

 Leach. But the fauna of the two pools is more interesting. 



The pool at Vale is in free communication with tlie sea, 

 which is able to enter it at all tides. The species which 

 ordinarily live in fresh water are not numerous ; they are 

 larvai of Chironomus and some Pisidia. The marine types 

 are represented by Mysis chamaileon^ Idotea trie asp idata^ 

 Melita palmata^ Corophium longicorne^ Lat., Gammarus 

 locusta and G. marinus^ Sphmroma serratum, and Rissoa 



