HYLIDiE. — CVII. 183 



c. Forelipad and crown bony, rough ; skin slightly tuberculate ; sacrum not 

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

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



ScAPHiOPUS, 263. 



263. SCAPHIOPUS Holbrook. ((TKatpr), spade ; a-ouj, foot.) 



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

 yellowish 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 Batrar 

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



Family CVII. H.YLID.,5!. (The Tree 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 AcRis, 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. (d/cpi'j, 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. gryllun, 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. (ypuXXor, a pig.) 



265. CHOROPHILUS Baird. Cxopo'f' vhovxxs ; ^t'Xos, lover.) 



517. C. nigritrus (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. 



