GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1527 



GENERAL REMARKS AND RECAPITULATION. 



We continue with some general deductions from the tables, and a 

 recapitulation of some principles. 



A survey of all the great divisions of Crustacea, shows us that ex- 

 clusive of the Entomostraca, they are distributed, according to present 

 knowledge, as follows : 



a. Torrid zone. 6. Temperate zone. c. Frigid rone. 



Brachyura, . . 535 257 (34 a) 5 (4 6) 



Anomoura, . . 125 110 (15 a) 4 (1 6) 



Macroura, . . 148 125 (16 a) 29 (2 6) 



Anomobranchiata, . 82 33 (9 a) 2 



Isopoda, . . .56 208 (1 a) 21 (3 &) 



Anisopoda, 8 34 15 



Amphipoda, . . 82 157 83 (4 6) 



Total, . 1036 924 (75 a) 159 (14 6) 



Taking the sum of the Frigid and Temperate zone species (subtract- 

 ing the fourteen common to the two) we have 1036 species in the 

 torrid regions to 1069 in the extra-torrid, seventy-five of which are 

 common to the two. This shows a nearly equal distribution between 

 the zones. But excluding the Brachyura, the numbers become 501 to 

 811, giving a preponderance of more than one-half to the Temperate 

 zone.* 



* Adding to the numbers above, the species which have been necessarily left out as of 

 uncertain locality, amounting to one hundred and. forty in all, and inserting also the 

 Entomostraca, it makes the total of described living species, as follows : 



Brachyura, t 830 



Anomoura, ..... 262 



Macroura, ..... 297 



1389 



Anomobranchiata, .... 115 



, Isopoda, ...... 295 



Anisopoda, ..... 57 



Amphipoda, ..... 341 



693 



Entomostraca, . . . . . 492 



Total, . . 2689 



The number of species collected in the course of the cruise of the Expedition (exolu- 



