THE BATRACHIA OF NORTH AMISJICA. 321 



abdomiual iutegumeut as au adhesive support, as this faculty is no- 

 where better seen than in the Acris, where derm is free. This creat- 

 ure will adhere for days to a vertical glass plate, not ouly by the abdo- 

 men and digits, but by the iuterdigital membranes, and will light se- 

 curely from a loug leap on such a surface. Daudin and Dumeril have 

 related the same adhesive faculty in Pelodytes punctatus, which is not 

 known in regard to the dermal attachments, but has not the abdominal 

 areohiB present in Acris. The extent of the attachment is least where 

 the dilatations are smallest, as follows: 



Abdomeu entirely attached ; 18 sp.* 



Phylloiuediisa four sp. Agalycbuis three sp. Trachycephalus two sp. Noto- 

 trerua oue sp. Seytopis two sp. Smilisca baudinii. 



Hypsiboas albomargiiiata, boaus. Hyla agrestis, krefftii, phyllochroa. 

 Posterior half or third of abdouieu attached; lateroveutral baud wide. 



Tripriou petasatns. 



Hyla fusca, arenicolor, gratiosa, versicolor, femoralis, squirella, andersonii, ccb- 

 rulea. 



Kauoidea aurea. 



Chorophilus triseriatus. 

 Less than posterior third abdomen attached; the lateroventrals wide. 



Hyla arborea, regilla, lateralis, miotympaauin, pickeringii. 



Chorophilus nigritus. 

 Abdomen entirely free. 



Hyla leseurei, curta, gracilipes. Acris gryllus. 



Of distinguishing features, which are seen in the degree of develop- 

 ment of the elements of the skull, there are, first, the development of 

 the o. 0. frontoparietalia ; second, of the prefrontalia ; third, of the su- 

 perficial cranial rugosities; fourth, of vomerine teeth; fifth, of a post- 

 frontal arch; sixth, of the ethmoid arch. 



Whole number of species 183 



Frontoparietals fully developed 22 



Frontoparietals with rugosities penetrating derm 9 



Prefrontals developed 17 



No vomerine teeth 6 



A postfroutal process 1 



Ethmoid incomplete above 1 



Of the above characters the lack of vomerine teeth is inconstant in 

 Phyllomedusa, being present in some and wanting iu other species. 



There is a tendency to the Pseudis and liana liberation of the outer 

 metatarsus in Hyla americana, hyposticta, and dimolops,iiii(\ M. flianoideaj 

 aurea. 



Parotoid glands occur in some species of Hylidte as au extensive stra- 

 tum of crypts, but never exhibit the definition seen in Bufouiform and 

 some Cystignathid genera. It even occurs in Seytopis venulosus irreg- 

 ularly, being sometimes present and sometimes wanting in the female, 

 at least. 



The xiphisteruum exhibits the form which exists in the greater num- 

 ber of Cystignathidte, exceptiug in eight species, where it only lacks 

 the posterior emargination. 

 1951— Bull 34 21 



