20 B A T R A C H I A. 



extremity of the lower jaw to the middle of the abdomen. The 

 limbs underneath show similar traces of maculas. 



Specimens of this species were collected on Puget's Sound, Oregon, 

 in May, 1841. 



We consider as belonging to the same species, a dozen of immature 

 individuals, collected on Columbia River, Oregon. 



Plate II, fig. 1, represents Rana aurora, size of life, and in profile. 



Fig. 2, is a profile of the head. 



Fig. 3, an outline of the head, seen from above. 



Fig. 4, an outline of the same region, from beneath. 



Fig. 5, under surface of the right hand. 



Fig. 6, under surface of the right foot. 



2. RANA PRETIOSA, B. & G. 

 (Plate II, figs. 13-18.) 



CAR. SPEC. Tympano parvo. Palmis planis. Plantis granulatis. 

 Palmarum digitis gracilibus et gradatim minuentibus. Plantarum 

 digitis palmatis ; longissimi solummodo terminali articulo libero. 

 Parvo planoque corneo processu in interioris digiti base ; minuto, 

 conicali, metatarsali tuberculo, inter quartum et quintum digitum. 

 Cute scortea, minutis granulis in anteriori, majoribus in posteriori 

 dorsi parte, et in abdominis lateribus, cooperta. Dorsali pororum 

 serie in utroque latere. Qlandulari carina per longitudinem maxillae 

 superioris. 



SPEC. CHAR. Tympanum rather small. Hands smooth. Feet under- 

 neath granulated. Fingers slender and tapering. Toes webbed ; 

 terminal joint of longest one alone free. A small and flattened 

 horny process at the base of the inner toe, and a minute, conical, 

 metatarsal tubercle between the fourth and fifth toes. Skin leathery, 

 finely granular on the anterior portion of the back ; more coarsely so 

 posteriorly, and on the sides of the abdomen. Two depressed dorsal 



