HYLID^. — CVII. 183 



a. Forehead and crown bony, rough ; skin slightly tuberoulate ; sacrum not 

 co-ossified with coccyx ; vomer with teeth : heel with a spadelike pro- 

 cess covered by a horny sheath ; toes more or less webbed. 



ScAPHiopus, 283. 



263. SCAPHIOPUS Holbrook. (aKa^rj, spade ; vovs, foot.) 



515. S. holbrooki Harlan. Spade-foot. Olive brown, a, 

 yellowisli band on each side. E. U. S., rare W. of Penn. ; bur- 

 rows in the ground ; extremely noisy in spring. " The machinery 

 for producing sounds equal to an ordinary steam whistle is ap- 

 parently confined to the throat of this rare and curious Batra- 

 chian." {Abbott.) L. 3. (To Dr. J. E. Holbrook.) 



Family CVH. HYLID^. (The Tkee Frogs.) 



Fingers and toes more or less dilated into viscous disks at their 

 tips ; upper jaw and vomer with teeth ; lower parts usually covered 

 with small warts; ear well developed. Genera 14; species 170; 

 found in most warm regions, especially abundant in tropical Amer- 

 ica; noted for their loud and varied voices, some of them being 

 heard at all times from early spring until frost comes. 



a. Disks small ; fingers not webbed ; palustrine. 



b. Toes broadly webbed ; tympanum indistinct. . . . . Ackis, 264. 



bb. Toes scarcely webbed ; tympanum distinct. . . Chorophilus, 265. 



aa. Disks round, conspicuous; fingers somewhat webbed; skin roughened; 



arboreal Hyla, 266. 



264. ACRIS Dumeril & Bibron. (Juipls, locust, from its 

 sharp note.) 



516. A. gryllus Le Conte, Cricket Frog. Hind legs very 

 long. Brownish above ; middle of back and head bright green 

 or reddish brown ; a dark triangle between the eyes ; sides with 

 three oblique blotches ; a white line from eye to arm. L. 1^. 

 E. U. S., in swamps, not on trees ; var. gryllus, S., N. to S. 111. The 

 northern form is var. crepitans Baird. Its snout is more blunt and 

 the inner surface of thigh not reticulate; its note resembles the 

 rattling of pebbles. (ypvXKos, a, pig-) 



265. CHOROPHILU8 Baird. (xopos, chorus ; (piKos, lover.) 



517. C. nigritua (Le C). Swamp Tree Frog. Bluish ash, 

 a dark dorsal stripe from snout backward, bifurcating above middle 

 of body ; a stripe on each side of this and one on side of head 

 and body, the latter pale-edged below. L. 1. Variable. In swampy 

 ground, rarely in trees. Its voice is a " rattle with a rising inflec- 

 tion at the end " (Cope), or like the scraping of a coarse-toothed 

 comb. 



