HYLID^E. CVII. 183 



c. Forehead and crown bony, rough ; skin slightly tuberculate ; 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, 263. 



263. SCAPHIOPUS Holbrook. (OVCCI^T;, spade ; vovs, 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 Batra- 

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



FAMILY CVII. HYLID^. (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. (aKpis, 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. (ypvXXos, a pig.) 



265. CHOROPHILU6 Baird. (Dope's, chorus; $i\os, lover.) 



517. C. nigritus (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.I. 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. 



