THE YOUNG NATURALIST. 



Tkera variata. Very common. 



„ firmata. Not so common as 



the last. 



Yysvpetes impluviata. Rather scarce. 



., elutata. Common. 

 MelantMa rubiginata. Common, but local. 

 „ oeellata. Not uncommon. 

 „ albicillata. Captured most seasons 

 Melanipjpe hastata. Very rare. 

 „ rivata. Scarce. 

 „ substristata. 

 „ montanata Very abundant. 

 ,, galiata. Rather scarce. 

 „ fluctuata. Common 

 Anticlea badiata. Common 



„ derivata. 

 Coremia prqpugnata. 



,, ferrugata. Frequent occurrence. 

 ,, unidentaria. Common. 

 Camptogramma bilineata. Common. 

 Phibalapteryx lignata. Scarce. 

 Seotasia dubitata. Not uncommon. 



„ certata Rare. 

 Cidaria eorylata. Has been taken at 

 Little Eaton by 

 Mr. J. Hill. 

 (To be continued.) 



THE 



CRABS, LOBSTERS, AND 

 SHRIMPS 

 OP THE CHESTER DISTRICT. 



By Alfred O. Walker, F.L.S., Chester. 



In the following sketch of the Crustacea, 

 I do not propose to go into any details of 

 internal structure. I may refer those who 

 wish to study these to Professor Huxley's 

 admirable work on the Cray-fish; also 

 to the Manual of Invertebrate Animals, by 

 the same author ; the article on Crustacea in 

 the current edition of the Encyclopaedia 



105 



Britannica ; and the Histoire Naturel des 

 Crustacies by Milne Edwards. 



The Crustacea belong to the immense 

 division of the sub-kingdom Annulosa, 

 known as the Arthropoda or Articulata, 

 from possessing jointed and articulated 

 limbs. This division includes the insects, 

 spiders, and myriapods (Centipedes) as well 

 as the Crustacea, which latter class is, 

 broadly speaking, separated from the others 

 by having their breathing apparatus in the 

 form of branchiae, or gills, and not tracheae. 

 They are divided into two sub-classes, viz., 

 Thoracipoda, or Malacostraca, which in- 

 cludes all those with which we have to do 

 at present, and Gnathopoda, or Entomos- 

 traca. 



The Malacostraca are divided into two 

 "legions" — Podophthalmia or stalk-eyed, 

 and Edriophthalmia or sessile-eyed Crus- 

 tacea. To the former belong all those 

 mentioned in the title of this paper, 

 strictly speaking, for some of the latter class 

 are also popularly known as shrimps, such 

 as the fresh-water shrimp or Gammarus. 



The Podophthalmia are divided into two 

 orders, viz., Decapoda ^ten-feet), to which 

 belong all the edible Crustacea ; and Stoma- 

 poda (mouth-feet j, a small and unimportant 

 order. The Decapoda again are divided 

 into three sub-orders, viz., Brachyura (short 

 tails), crabs proper; Anomoura (irregular 

 tails), hermit crabs, &c. ; Macroura (long 

 tails), lobsters, prawns, shrimps, &c. 



i. Brachyura. — These are the most high- 

 ly organized of the Crustacea and include 

 the largest species. At the head of them 

 stand the sub-tribe Oxyrhyncha (sharp 

 beaks), so called from the carapace or shell, 

 which is generally more or less pear-shaped, 

 with the narrow end in front, terminating 

 anteriorly in a rostrum or beak. To this 

 sub-tribe belong the various species of 

 spider-crabs, including the gigantic Inachus 

 Kampferi of Japan. It is represented on 

 the shores of our district (the River Dee or 



