200 [DecrMbBrr, 
Locality. San Luis Obispo, California. 
This huge species is imbedded ig fyiable limestone which contains abun- 
dance of siliceous sand rounded by attrition. No other fossil can be de- 
tected in the portions of limestone which accompany the specimens. 
Cretaceous Species. 
PHo.Las. 
Pholas pectorosae Ovate-cuneate; anteriorly inflated, contracted in the 
middle; posterior side cuneiform; disk with radiating ribs, largest anteriorly, 
and interrupted by concentric furrows; anterior side very short, margin ob- 
tusely rounded or subtruncated; basal margin rounded anteriorly, contracted 
medially, straight posteriorly. 
Locality. Tinton Falls, Monmouth Co., N. J. 
This rare species was found by the jate Lardner Vanuxem. It is a cast, on 
the right valve of which an impressed line runs obliquely from the apex, while 
Qn the opposite valve there is a corresponding furrow, and the three ribs nearest 
the posterior end are more remote from each other, than in the right valve. 
Inoceramus, Sow. 
Tnoceramus Sensent. 
Rounded; both valves profounc dly curved; beaks involute, the volutions of 
the larger valve, 3, contiguous in both valves. Length 1§ inches; width 23 in. 
Loeality. Missouri river, Nebraska. Mr. Senseny. 
Inoceramus perovalis. Oval, convex, slightly oblique; beaks medial, both 
dorsal margins equally declining ; basal margin acutely rounded ; surface with 
obsolete concentric undulations. Height about 1} inches; length less than the 
height. 
Locality. Chesapeake and Delaware Ganal. Mr. Vanuxem. 
The Committee on papers by Dr. Woodhouse—namely, “ Descrip- 
tion of two new species of Pouched Rats,” and ‘“ Description of a new 
species of Struthus,” reported in favor of publication in the Pro- 
ceedings. 
Description of a New Species of Pouched Rat, of the Genus Perognathus, Wied. 
By S. W. Woopnouse, M.D. 
-PEROGNATHUS PENECILLATUS.~ 
Characters. Above yellowish brown, beneath white, tail longer than the 
head and body, penecillate, with bright brown hair. 
Form. Head of moderate size, not easily distinguished from the neck ; 
incisors small and partially exposed, upper ones sulcate in the middle. 
Nose small and rather pointed, extending some distance beyond the incisors ; 
whiskers light brown, irregularly mixed with black; eyes dark brown, and of 
moderate size; ears nearly round and moderate, almost naked anteriorly and 
covered posteriorly with fine brown fur; the tragus and antitragus are quite 
prominent. ‘The external meatus is protected by a tuft of short black bristles 
extending across the ear. Tail about one and a quarter inches longer than the 
head and. body, round, gradually tapering, and covered with hair; on the supe- 
rior and middle portion commences a row of long silky hairs, which gradually 
increase in width until they form a tuft at the end. Fore legs short, feet small, 
with four well developed toes and a short thumb, which is armed with a nail ; 
palms naked. . Hind legs and feet long, having fel toes, terminated by nails. 
Feet and toes covered with short fine fur; soles naked. ‘The fur longer on the 
back than on the belly; it is thick, soft and silky. 
