340 LOWER VERTEBRATES. 



The PHRTNiscLDiE are found in tropical America, Malaysia, New Guinea, and Mada- 

 gascar. Of twenty-two species, sixteen belong to tropical America. Species of Phry- 

 niscus are found from Buenos Ayres to Costa Rica. Some of them are toad-like in 

 appearance, while others are of more elongate proportions ; most of them are strik- 

 ingly or brilliantly colored. The P varius is common in Costa Rica. It is black 

 above, with spots which may be red or green, and these may be confluent over the 

 back, so as to exclude the dark color. The P. longirostris has a dermal process on 

 the end of the muzzle. Prachycephalus ephippium is a small species which is com- 

 mon in some parts of Brazil. It looks like a small toad, and has a saddle-like bony 

 plate in the integument of its back. It is bright yellow. In the Central American 

 and Mexican genus, Sypopachus, we have the short conic head of the genus Engy- 

 stoma ; the Malaysian genus Calophrymcs, and the Sphenopliryne from New Guinea 

 have the same form. In the single Brazilian species of Stereocyclops, we have the 

 same form, but much depi-essed, so that it resembles an undersized Pipa. The skin 

 has an incrustation which thickens it, and the eyeball has an osseous ring surrounding 

 the pupil. It is leather 'brown, with a narrow white median dorsal line. Its habits 

 are subterranean or perhaps subaquatic. 



In ■ the Engtstomidje the range of form is even greater than in the Phryniscidse. 

 Thus in Microhyla the form is often slender, and the feet are webbed for an aquatic 

 life. In Callula the foi-m is more robust. Both these genera are eastern and southern 

 Asiatic. The species of Engystoma are American, and are of quite small size. One 

 of them inhabits the southern regions of the United States. In the spring it lives in 

 the water, from which it jDrojects its muzzle far enough to utter its very nasal monot- 

 onous cry. When alarmed it withdraws itself so quickly and quietly that it is very 

 difficult to discover. In Xenohatrachus, which has a single species found in New 

 Guinea, the dentition is peculiar in the presence of a single long tooth on each pala- 

 tine bone. The species of the tropical Asiatic genera Cacopus and Glyphoglossus 

 are almost globular in form, especially when distended with eggs. Hremceps and 

 Phrynomantis of South Africa are distinguished by the very weak ossification of the 

 skull. The latter has digital dilatations, but lives in the ground. 



The Dyscophid^ include but eight species, which fall into five genera. All the 

 species except one from Pegu inhabit Madagascar. Some of them are remarkable for 

 the beauty of their coloration. 



The most extensive family of the Firmisternia is that of the Ranid^. It em- 

 braces two hundred and forty-eight species, which are referred to eighteen genera. 

 This large family is almost excluded from the neotropical and Australian realms, 

 Mexico and Central America being the only part of the former which is furnished 

 with them, except a few restricted types in the northwestern part of South America. 

 They reach their highest development in the East Indies, where many genera and 

 species are found. The family includes a few subterranean species, and numerous 

 aquatic and arboreal forms. We do not meet in this family with the horny processes 

 for securing the attachment of the sexes, found in some of the Cystignathid», but the 

 firm structure of the sternum renders the grasp of the male more solid, and also 

 renders the thorax of the female less compressible. In most of the family both the 

 anterior and posterior sternal elements (mantibrium and sternum proper) are furnished 

 with an osseous style. In the South American genus Prostherapis the sternum is 

 membranous and rudimentary, but the manubrium is ossified, while in Colostethus, of 

 the same region, both manubrium and sternum are membranous or wanting. Both of 



