NO. 2123. CRUSTACEA COLLECTED IN COLOMBIA— PEAR8E. 539 



In Colombia there is a gradual decrease in the number of species 

 of crustaceans in going from the shore inland. In the present paper 

 14 species are recorded from Santa Marta on the coast, 16 at Funda- 

 cion in the low country a little way back, 10 at ''La Kosa," which 

 is about 7 miles from Santa Marta, 12 at the Cincinnati Coffee Plan- 

 tation at an altitude of 4,500 feet, and 4 (aU isopods) on San Lorenzo 

 (a mountain which reaches an altitude of 8,300 feet). The distri- 

 bution of species in local habitats was as follows : 



Forest, 15 — on ground, 12; under logs, 10; near streams, 9; in 

 trees, 3; in bromeliads, 2. 



Streams, 12 — larger rivers, 8; mountain brooks, 5 (7); in pools in 

 brooks, 6. 



Swamp, 11 — in puddles, 8; open water, 5; land about margin, 2. 



Desert, 1 — (Coenohita). 



GEOGRAPHICAL AFFINITIES OF THE CRUSTACEANS OF THE SANTA 



" MARTA REGION. 



Of the Entomostraca collected, five of the cladocerans and the 

 ostracod are species which have previously been taken in the south- 

 eastern United States. They will doubtless be found to have a wide 

 distribution when their range is known. Diaptomus marshi has been 

 recorded from Guatemala and Panama. Cyclops leuckarti and 

 Macrothrix laticornis are cosmopolitan. 



The shrimps and prawns are for the most part species which range 

 from the southern United States to Brazil. Peneus hrasiliensis 

 ranges north to Massachusetts, and Atya scahra is found in Africa. 

 Coenohita diogenes occurs in the West Indies, Africa, and some of the 

 Pacific Islands. 



Two genera of land crabs (Potamonidae) were collected near 

 Santa Marta. Of the three species of Trichodactylus, two range east 

 and south to Brazil, the other northwest to Nicaragua. The four 

 species of Pseudothelphusa described by Miss Rathbun are related to 

 species which are found south and west. The different species 

 therefore have relations in every direction. The marine crabs are 

 aU species which have a wide range on the Atlantic coast of both 

 Americas, some even extending to Africa and other continents. 



The isopods which are not new range through Central America 

 and the West Indies, one extending to Bermuda and the Mediter- 

 ranean. Doubtless many of them reach farther to the south, but 

 their distribution in that direction is unknown. 



The crustaceans treated in this paper add nothing of great impor- 

 tance to what is Imown concerning the distribution of the carcino- 

 logical fauna of South America and the West Indies. The land 

 crabs mostly range southward, the entomostracans and isopods north- 

 ward, but the latter premise may be found to be erroneous when the 



