Zoology of Panama. 3317 



the surface, and are driven motionless against the net, where they are 

 secured. The law has inflicted a punishment upon this mode of fish- 

 ing, as it not only depopulates the rivers, but causes diseases among 

 a people who use river-water for every domestic purpose. 



Shells occur in great variety and beauty, and belong principally to 

 the genera Area, Avicula, Buccinum, Cancellaria, Cerithium, Chiton, 

 Clavagella, Columbella, Conus, Corbula, Cypraea, Harpa, Marginella, 

 Murex, Micula, Neaera, Oliva, Ostraea, Patella, Pecten, Phos, Pinna, 

 Purpura, Pyrula, Scalaria, Solarium, Terebra, Triton, Trophon and Ve- 

 nus. Species of Area and two kinds of oysters are used as food : a pur- 

 ple die is obtained from the Caracolilla {Purpura patula, Linn.), and 

 pearls from the Avicula margaritifera, Bruguiere. Pearl-oysters are 

 common on the whole coast of the Pacific Ocean, but are more abun- 

 dant in the Bay of Panama. Balboa, when exploring the South Sea, 

 was the first European who heard of their existence, having been pre- 

 sented with some pearls by the Cacique Tomaco. Shortly after this 

 occurrence (J 513) the pearl-fishery commenced, and has continued 

 ever since. At present it is carried on by free labour, a diver receiv- 

 ing, besides his daily food, 15 dollars a month. In each dive, if suc- 

 cessful, he is able to bring up a dozen shells, four of which he puts 

 between the fingers of the left hand, and eight in the bend of the same 

 arm, while his right remains free, for separating the shells from the 

 rocks. The divers complain of the Aguaraalas, or sea-nettles, species 

 of Medusa, which cause a severe pain when touching the body, but 

 they dread the shark, so frequently fatal to them. About thirty years 

 ago, a diving-bell was sent out by an English company, but it did not 

 answer expectation ; the expense at which the concern was fitted out 

 and supported was too great, and the oysters did not lie in banks, but 

 were dispersed under rocks, and in uneven ground, while a peculiar 

 ground swell and motion under the water, with a strong current, made 

 it almost impossible to place the diving-bell in safety and to advan- 

 tage. On being opened, scarcely a tenth part of the shells contain 

 pearls, and even among those are many gray and bad-shaped ones, of 

 little or no value. The pearls are sold by weight, varying in price 

 according to shape and colour. The largest and most perfect one 

 perhaps ever found on the coast of the Isthmus, was obtained at the 

 Paredez Islands, and is in the possession of Mr. James Agnew, in 

 David : it is three quarters of an inch in diameter, and perfectly 

 round. The shell is a lucrative article of commerce, and much in- 

 quired after by French vessels ; the animals themselves are strung 

 upon a cord, dried in the air, and eaten. 



