258 PALEOZOIC PALEONTOLOGY. 
MOLLUSCOIDEA. 
BRACHIOPODA. 
HYATTELLA? LAMELLOSA n. sp. 
Plate XXIII., Figs. 15-18. 
Description.—Shell small, transversely subelliptical in outline. 
Pedicle valve prominent on the umbo; the beak blunt, not strongly 
incurved; the surface curving rather abruptly from the umbo to the 
cardinal margin, and sloping gently, with a slight convexity, to the 
lateral margins; toward the front it is deeply depressed in a broad, 
somewhat flat-bottomed sinus, which reaches to the umbo. Brachial 
valve strongly convex, most prominent near the middle; the mesial 
fold not strongly elevated above the general surface, with a slght, 
depressed, mesial line. Surface of both valves marked by strong and 
broad, concentric, lamellose lines of growth. 
The dimensions of the type specimen are: length, 6 mm.; width, 7 
mm.; thickness, 4 mm. 
Remarks.—This species is established on a single, nearly-perfect 
individual, which is of interest, because it is the only specimen of 
brachiopod which has been observed in the strata of the Rondout for- 
mation in New Jersey. All other recognizable species which have been 
found in the formation are ostracodes belonging to the genus Leper- 
ditia. The generic position of this little brachiopod is uncertain, as 
its internal characters cannot be determined from the single specimen. 
Its general form is strongly suggestive of a diminutive individual of 
the Carboniferous species, Athyris lamellosa. It seems to have a 
general outward similarity with the species of the genus Hyattella, and 
it is therefore placed in that genus provisionally. 
