488 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



two and two-tliirds times in the total length, or, then, a proportion 

 of 37.50 per cent. Careful and repeated measurements of the types of 

 laticeps show that the widest head from among 9 specimens is only 

 34.78 per cent, while there is 1 as narrow as 31.44 per cent, and the 

 average is 33.08 per cent. The types of curta, from practically the 

 same locality, have extremes of 35.19 and 32.11 per cent, and an average 

 of 33.67 per cent. 



The accompanying table will serve to show more plainly the propor- 

 tions of specimens from some of the different localities: 



Proportions of Hyla regilla. 



Locality. 



Vancouver Island, British Co- 

 lumbia 



Fort Vancouver, Wasbington. 



Pugi-t Sound, Washington 



Sboalwater Hay, Washington. 



Walla Walla, Washington 



Fort Unipqua, Oregon 



Fort Klamath, Oregon 



"Oregon " 



Sonoma County, California... 



Lake Tahoe, California 



Monterey, California 



Santa Barbara, California 



Santa Cruz Island, California. 



Old Fort Tejon, California 



Panamint Mountains, Califor- 

 nia 



Hot S])ring8 and Saratoga 

 Springs, California 



Ash Mi'adows, Nevada 



Oasis Valley. Nevada 



Palii'ump Valley, Nevada 



Between Palirump and Vegas 

 valleys, Nevada 



Vegas Valley, Nevada 



Ogden, Utah 



San Diego, California 



Santa Ysabel, California 



Average from San 'Diego 

 County, California 



Cape St.' Lucas, curta 



Cape St. Lucas, laticeps 



Average of last two 



Num- 

 ber of 

 speci- 

 mens. 



Aver- 

 age 

 length. 



nun. 

 40.00 

 24.t)0 

 26.28 

 47. 00 

 30.50 

 35.00 

 35.87 

 25.45 

 31.50 

 22.89 

 33.05 

 30.04 

 35.45 

 33.60 



36.32 



28.65 

 27. 00 

 27.45 

 26.90 



38.00 

 25.80 

 40.00 

 28.40 

 30.64 



29.68 

 26.30 

 33.88 

 29.14 



Ratio of head to body. 



Broad- Narrow- Aver- 

 est. est. age. 



34.21 

 34.70 



33.93 

 34.18 

 34.09 

 35.42 

 34.48 

 36.17 

 36.76 

 36.06 

 38.24 

 36.42 



39.48 



37.40 

 35.18 

 37.28 

 35.48 



36.50 

 38.46 



34.00 

 32.27 



35.19 



34.78 



31.88 

 30.90 



32.79 

 31.17 

 31.83 

 31.92 

 31.49 

 31.25 

 33.33 

 32.56 

 33.68 

 31.82 



34.67 



32.49 

 31.74 

 34.54 

 32.44 



35.90 

 35.01 



31.58 

 32.14 



32.00 

 31.44 



35.81 

 33.11 

 32.38 

 31.92 

 33.34 

 32.23 

 33.07 

 33.58 

 33.17 

 33.73 

 34.66 

 34.15 

 36.46 

 33.79 



36.83 



34.78 

 32.90 

 35.61 

 34.04 



36.20 

 36.87 

 32.56 

 32.79 

 33.52 



33.38 

 33.67 

 33.08 

 33.44 



Eatio of tibia to body. 



Long- Short- Aver- 

 est. 



50.00 

 52.50 



49.80 

 49.35 

 52.27 

 52.00 

 52. .10 

 52.77 

 52.33 

 52.27 

 51.51 

 52.50 



52.11 



50.00 

 49.12 

 46.40 

 50.00 



47.30 

 48.71 



52.33 

 50.91 



50.94 

 51.61 



47.82 

 47.87 



46.42 

 48.10 

 45.16 

 48. 08 

 46.46 

 47.91 

 48.57 

 47.76 

 47.43 

 48.57 



46.15 



46.51 

 45.83 

 44.23 

 45.60 



46.15 

 44.00 



49.09 

 47.00 



48.00 

 45.07 



47.50 

 49.53 

 49.78 

 48.93 

 47.74 

 48.53 

 48.51 

 50. 12 

 48.60 

 50.14 

 50.39 

 49.74 

 49.89 

 50.58 



49.44 



47.96 

 47.83 

 45.00 

 47.83 



46.72 

 46.23 

 51.25 

 50. 09 

 48.66 



49.28 

 49.87 

 49.24 

 49.66 



From the above it will be seen how close together the averages run, 

 especially in regard to head proportions, though there is not much 

 variation in those of the tibise. Still, in the desert localities, the legs 

 become a very little shorter and at the same time the head a trifle 

 broader, the animal assuming rather more of a squat form, in accord- 

 ance with its changed surroundings. As a rule, the gradations show 

 beautifully — as, for instance, in passing from Pahrump to Vegas valleys. 

 It appears that the northern specimens have rather narrower heads 

 than those farther south, and particularly when compared with the 

 desert forms, but the difference is so slight and so inconstant as to 

 make it impracticable as a basis for nomenclatural distinction. 



Of the North American hylas, regilla is one of the most limited in 

 the extent of the digital disks and webbing of the feet. Although 



