256 



CRUSTACEA OF NORTHUMBERLAND AND DURHAM 



Crustacea of Nortlminherland and Durham compared with 

 those of some other parts of the country and seas : — 





)-4 





 13 2^ 



t3 " 





<a-. 

 ON 



t*H 



ON 



00 10 



^CO ON 





Northum 

 land ai 

 Durha 



Chanr 



Islands, 



Devon i 



Cornwi 



1906 



CO MD 



Firth 

 Clyde, I 



Firth 

 Forth, I 



Shetlai 

 Marine I 

 Inland i 



Brachyura 



22 



39 



41 



27 



29 



19 



18 



Anomura 





15 



II 



16 



12 



16 



15 



17 



Macrura 





22 



26 



32 



22 



27 



18 



20 



Schizopoda 





14 



18 



29 



16 



25 



26 



II 



Stomatopoda 







I 



2 



— 





— 



— • 



Sympoda 





26 



9 



13 



17 



31 



21 



12 



Isopoda 





58 



52 



68 



23 



62 



44 



23 



Amphipoda 





130 



136 



144 



130 



168 



145 



"3 



Branchiopoda — 

















I. Phyllocarida 



I 



— 



I 



I 



I 



— 



I 



2. Phyllopoda 



— 



— 



I 



— 



— 



— 



— 



3. Cladocera 



48 



— 



34 



2 



51 



54 



Z1 



4. Branchiura 





— 





— 



I 



I 





Ostracoda 



121 



64 



107 



58 



142 



132 



99 



Copepoda 



163 



3t 



293 



195 



290 



306 



70 



Cirripedia 



17 



— 



27 



10 



12 



13 



6 







(>11 



387 



S08 



513 



855 



794 



427 



The character of the fauna of the coasts of Northumberland 

 and Durham is disthictly boreal, and much more northern 

 than that of the same latitude on our western shores. As 

 long ago as 1868 one of us wrote, "The distribution of animal 

 life around our coasts appears for the most parts to have 

 followed the direction south, west, north, and east. It would 

 seem that comparatively few (if any) southern species have 

 made their way far north through the Straits of Dover, 

 v/hich may probably be accounted for by the fact that that 

 channel has, geologically speaking, been only a short time 

 open. As a rule southern species are to be seen at a higher 

 latitude on the western than they are on the eastern coasts. 

 There are, however, some apparent, but only apparent ex- 

 ceptions. These consist of animals known on the north-east 

 coast of Scotland, which we should not have expected to meet 

 with there. On examining into the probable cause of their 

 migration to this district, I am led to believe that they have 



