COPEIA 21 



same brook furnishes, compared to its size, a wider 

 swimming range. 



The evolution in habit and structure which from 

 a group of predaceous free-swimming mammals like 

 the Delphinidae has evolved the large whale-bone 

 whales which feed on small animals sifted from the 

 water with their baleen, is more or less paralleled in 

 several independent groups of fishes. Our common 

 menhaden, representative of the herrings, is a good 

 example. Though a small fish the size and density 

 of the schools in which it swims are in a way analagous 

 with the cetacean's bulk. Continually it swims for- 

 ward, its mouth wide open, gulping sea-water from 

 which its very fine lengthened gill-rakers are sifting 

 food enough to make it very fat and sought after for 

 its oil. A better example are the gigantic basking 

 shark and whale shark, off-shoots from the active pre- 

 daceous mackerel sharks. The large gill openings 

 and very small teeth of these largest of fishes, show 

 them to be sifters of small food. In the almost uni- 

 versally predaceous mackerel genus Scomber an East 

 Indian species has very long fine gill-rakers, doubtless 

 associated with herring-like feeding habits. 



J. T. Nichols, 

 New York, N. Y. 



CONCLUDING NOTES ON THE SALIEN- 

 TIA OF JACKSONVILLE, FLA. 



Acris gryllus, Le Conte, the "Cricket frog," is 

 one of the commonest frogs, great swarms of this 

 species having been seen by the writer during the 

 spring months about the edges of bayous, creeks and 

 ponds. Its rattling notes can be heard during the 

 entire warm season, day and night. Owing to the 

 small size of its adhesive disks, this tree-"frog" can- 

 not climb into trees, but lives on the ground, wander- 

 ing into fields, meadows and gardens. It attains a 

 length of 1*4 inches from snout to vent, but the 



