CRUSTACEANS 



The Romans were a highly practical people, and the poet of 

 widest renown among them has left us the aphorism that it is im- 

 possible for every one to do everything. It appears to be equally true 

 that all counties cannot embrace all branches of natural history with a 

 complete efficiency. A region may have striking features of scenery 

 appealing not only to aesthetic tastes but to the curiosity of those who 

 would fain understand the slow moulding of the land they live in and 

 unravel the far-off story of what happened before its history began. In 

 such a region there may be a great variety of attractive objects, fossils 

 and minerals, exquisite fluor spar, marbles of great beauty and value ; 

 there may be mysterious caverns with wonderful stalactites and bones of 

 extinct yet half familiar animals ; there may be dripping wells in which 

 treasures the most trifling or the most precious a tuft of moss, the 

 egg of a robin, or a skull which the owner has ceased to require 

 may be rendered almost imperishable by a calculated thickness of in- 

 crustation. Since all these and several other engaging attributes belong 

 to Derbyshire, there is no great reason for surprise that the subject of 

 this chapter has hitherto been passed over with an almost absolute 

 neglect. It is time that its turn should come, and an endeavour will 

 here be made to show that carcinology, the science and study of 

 crustaceans, has a fair and promising field in this county. 



It will be tolerably obvious to every reader that in regard to this 

 pursuit there are facilities enjoyed by the maritime outskirts which 

 are entirely denied to the central districts of England. At any con- 

 siderable distance from the coast the majority of the inhabitants may 

 pass their whole lives without ever suspecting that any crustaceans what- 

 ever are fellow-tenants with themselves. They are impressed by the fact 

 that crabs and lobsters, prawns and shrimps have to be imported from 

 the sea and are never found indigenous to the midlands. It is not, or 

 till recently was not, any part of popular education to explain that in 

 close affinity with the commercial species just mentioned there are 

 others, not large, not eaten, not highly prized, which live on land and 

 on terms of an indifferent intimacy with mankind. Also among things 

 not generally known may be included the fact that, in addition to a 

 score or so of terrestrial species, we have about two hundred that occupy 

 the fresh waters of this country. 



Omitting the cirripedes or barnacles which are not tempted to 

 forsake our shores, we may divide the rest of the crustacean class into 

 Malacostraca and Entomostraca. It is the latter division that supplies a 



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