

THE BRACHYURA 



As dredging and shore collecting were of secondary importance during 

 the two cruises of the" Albatross " in the tropical Pacific, the adult Decapods 

 obtained by no means represent the complete fauna of the area visited. 

 Nevertheless, 136 species of Brachyura were obtained, and among them 18 

 species and one genus new to science. 



The majority of the new forms are from the Caroline Islands and the 

 Paumotu Archipelago, while two come from Easter Island. A remarkable 

 discovery is that of a Callinectes inhabiting Tahiti and the Fijis. The genus 

 is one heretofore restricted to middle America and the west coast of Africa. 

 The insular species, even as observed in the young, is a strongly marked 

 one. An addition to the deep-water fauna is a Scyramathia, dredged in 300 

 fathoms off the Galapagos. 



A young specimen of the shore crab, Grapsus long itar sis, only 6.5 mm. 

 wide, but having the form of the adult, was taken in the intermediate tow- 

 net, between 300 fathoms and the surface, at station 4717, about 600 miles 

 southwest of the Galapagos Islands, where the depth of the ocean is 2153 

 fathoms, and where the South Equatorial Current sweeps in a northwesterly 

 direction past the Galapagos towards the Mid-Pacific. It is not surprising, 

 then, that this species when full grown does not inhabit the Galapagos, but 

 is known to occur at the Paumotus, the Ellice, and the Hawaiian Islands. 

 If this single example is representative, the species is fully equipped for its 

 littoral life long before it reaches its final habitation. 



The type specimens described below are in the United States National 

 Museum. 



The drawings were made by Miss E. G. Mitchell, the photographs by Mr. 

 Clarence Dodge. 



