A HISTORY OF ESSEX 



county, makes the following observations : ' Common at all my stations. 

 Though sometimes free from such things, it is very commonly much 

 covered by small sponges, ascidians, and polyzoa, which seem to be 

 growing on the shell ; but, in some cases, many portions of the broken 

 leaves of Zostera marina are so attached as to make it almost certain 

 that they were intentionally so fixed by the animal.' According to the 

 generally accepted rules of zoological nomenclature this species is more 

 correctly called Macropodia rostrata (Linn.), the name of Linnasus being 

 added in parenthesis to indicate that he is responsible for the specific 

 name rostrata, but that the generic name Macropodia was assigned by a 

 later hand. The true names of some of our crabs are by no means easy 

 to determine. But those who scoff at zoologists on this account will 

 perhaps find themselves at a loss to tell the surnames of the kings and 

 queens of Europe or even those of the last and present sovereigns of their 

 own country. The two crabs which Mr. Lovett follows Bell in calling 

 Pisa tetraodon and P. gibbsii are called by Adam White respectively 

 Arctopsis tetraodon (Pennant) and A. lanata, Lamarck, while Mr. E. J. 

 Miers calls the latter P. (Arctopsis} tribulus (Linn.). The American 

 writer, Miss M. J. Rathbun, a high authority on the subject, thinks that 

 Lamarck's genus Arctopsis was too vaguely defined for identification. In 

 that case the two species will become Blastus tetraodon (Pennant) and 

 B. tribulus (Linn.), the generic name Blastus having been established by 

 Leach for tetraodon in precedence of the name Pisa which at the same 

 date he published for the other species. 1 Hyas araneus (Linn.) has an 

 extensive range, being not only a typical Essex ' spider,' but being found 

 large and fine and plentifully in arctic waters. Dr. Sorby says : ' This 

 is common all along the coast. It is often so much covered by ascidians, 

 sponges and other objects either growing or dead that when creeping on 

 the bottom of an aquarium it can scarcely be recognized as a crab.' H. 

 coarctatus, Leach, is usually smaller and descends into deeper waters, but 

 otherwise so resembles its frequent companion as to lie under some 

 suspicion of being a variety of it rather than an independent species.* 



According to Dr. Sorby's notes Cancer pagurus, Linn., the common 

 eatable crab, may be included in the Essex fauna, for ' though seldom if 

 ever dredged in the estuaries or near the shore it is caught by fishermen 

 outside.' The aloofness of the great crab is compensated by the fami- 

 liarity of the smaller eatable crab, Carcinus mcenas, for ' this is extremely 

 abundant everywhere along the coast and in the estuaries.' Of Portunus 

 bolsatus, Fabricius, Dr. Sorby says : ' This is fairly common in the 

 Crouch but less abundant elsewhere.' 



Of the Macrura anomala two very generally distributed British 

 species are reported by Dr. Sorby. Of the common hermit crab, 

 Eupagurus bernbardus (Linn.), he says : ' This is very abundant off 

 Mersea and also found at most stations. The colour of the animal and 

 of the bunch of eggs is well preserved when mounted as a lantern slide 



1 Edinburgh Encyclopedia, vol. vii. p. 431 (1814). 2 Ann. Nat. Hist, ser. 7. vol. v. p. 2 (1900). 



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