Marine Fauna of Great Britain. 41^ 



nophorus, and the viviparous Prosoi-ochmus, are characteristic. 

 The Euphrosynida3 amongst Annelids have their headquarters 

 as tidal forms in this region. Instead of the northern sea- 

 mice (Aphrodite and Lcetmatonice) , we have in abundance 

 the southern Hermione hystrix^ with its naked scales and 

 long barbed spines, in water from 10 to 20 fathoms. The 

 occurrence of Harmothoe areolata, Grube, H. marphysce, of 

 tlie Nereis [Eulalia) nebulosa of MontsLgn, o( Nereis Marionii 

 and the general prominence of Nereids, of the Eunicidse, 

 Lunibriconereidse^ Staurocephalus^ Chcetopterus^ Sahellaria al- 

 veolata, Leprcea and other Terebellids, Sahella saxicava, and 

 Protula and Filigrana between tide-marks, are diagnostic. 



In no group is the contrast greater than in the higher 

 Crustacea. The huge spiny lobster off rocky shores, velvet- 

 crabs, Pirimela and Ehalia under stones between tide-marks, 

 Alpheus ruber and Pagurus cuanensis in rock-pools, Pagurus 

 Prideauxii^ Maia^ Dromia, and Polyhius are all more or less 

 characteristic. In the same way the presence of Gymodocea 

 trancata and Sphceroma Prideauxianum in the fissures of 

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

 large Cymothoa on fishes, and other sessile-eyed crustaceans 

 are noteworthy. 



The extraordinary beauty and profusion of the Polyzoa, 

 such as the Escharidse and the Lepraliae, between tide-marks, 

 together with the finely spiral tufts of Bugula turbinata and 

 the free growth of Amathia lendigera and Flustra chartracea 

 (the two last from the inshore water), are also southera 

 features, as also is the occurrence of Argiope. 



The molluscan fauna is characterized by the presence of 

 extensive beds of large oysters in the inshore waters, with 

 the somewhat rare borer, Gastrochoina, perforating the upper 

 valve of many ; whilst amongst them are large Anomice. 

 Other typical species are Mactra glauca^ Triton nodifer^ 

 T. montacuti, Cardium papillosum, and Murex aciculatus. 



Between tide-marks we have Pecten varius, Mytilus bar- 

 batusy Area tetragona, and Galeomma Turtoni, a lamelli- 

 branch which opens its valves and adheres to the under 

 surface of stones. Only here does Haliotis (the ear-shell or 

 " ormer ") occur between tide-marks ; and in the rock-pools 

 no sight can be more striking than to watch Lima nimbly 

 moving through the water with its bright orange tentacles 

 forming an ornamental fringe. Trochus lineatus^ Murex 

 erinaceus and M. aciculatus, Aplysia, Gerithium, and Geriihi- 

 opsis are likewise characteristic of the tidal area, and Galyp- 

 trcea of the adjoining waters, along with numerous Octopij 

 which have their homes under the larger stones. 

 Ann. dc Mag. N. Hist. Ser. 6. Vol. xviii. 29 



