92 BULLETIN 194, UNITED STATES NATIONAL MUSEUM 



Subfamily Microhylinae Noble 



Microhylinae Noble, The biology of the Amphibia, 1931, p. 537. 

 KEY TO MEXICAN GENERA OF MICROHYLINAE 



1. Toes united by at least a vestigial web; precoracoids present; fingers free, 



not dilated at tips Hypopachus (p. 94) 



Toes free without or with but a trace of a vestigial web at base; finger 

 tips swollen or widened perceptibly; no precoracoids; coracoids united 

 by a simple cartilage Microhyla (p. 92) 



Genus MICROHYLA Tschudi 



Microhyla Tschudi, M6m. Soc. Sci. Nat. Neuchfitel, vol. 2, 1838 (1839), pp. 28, 

 71. — Parker, Monograph of the frogs of the family Microhylidae, 1934, 

 pp. 123-151. 



Gasirophryne Fitzinger, Systema reptilium, 1843, p. 33 (genotype Engy stoma 

 rugosum Dum^ril, Bibron, and 'D\.nn^v\].=^ Engy stoma cardinense Holbrook). 



Genotype. — ''Hylaplesia achatina" Boie, nomen nudum {=Microhyla 

 achatina Tschudi.) 



Range.- — Southwestern Asia, Malayan Islands, and the southeastern 

 quarter of the United States south to Brazil. 



Species. —About 13 forms in the Americas, and 15 Old World forms 

 are known; 5 occur in Mexico. 



KEY TO MEXICAN SPECIES OF MICROHYLA 



1. A single metatarsal tubercle 2 



Two metatarsal tubercles 4 



2. Toes swollen at tips but not wider than digit; ventral surface of limbs and 



abdomen immaculate 3 



Toes flattened at tips, perceptibly wider than the digit; ventral surface of 

 chin and throat, underside of limbs and side of head and body brownish, 

 with lighter flecks; central part of abdomen white with some brown 

 reticulation. _. elegans (p. 93) 



3. Head narrow; trace of a black stripe or row of black spots from behind 



eye to a point on side; foot slender, small mazatlanensis (p. 92) 



Head wider; no trace of black stripe behind eye; foot wider, the toes a 

 little longer proportionately, larger olivacea (p. 93) 



4. A hair-fine line from tip of snout to anus; a similar line from anus along 



posterior surface of leg to foot; smaller usta gadovii (p. 94) 



No hair-fine line on back or posterior surface of leg; larger. _ usta usta (p. 93) 



MICROKYI.A MAZATLANENSIS Taylor 



Microhyla mazatlanensis Taylor, Univ. Kansas Sci. Bull., vol. 29, 1943. pp. 

 355-357. 



r?/pe.— EHT-HMS No. 1236. 



Type locality. — 2 miles east of Mazatlan, Sinaloa, Mexico. 



Range. — Known only from the type locality. 



