[MarTTHEW] ORDOVICIAN SYSTEM ON THE ATLANTIC COAST 259 
LINGULA, Bruguiere. 
Lineuta How teyt, n. sp., PL I., Figs. 3a and b. 
Among the fossils sent me by Mr. Howley was a large Lingula of 
peculiar shape. 
General form quadrate, with obtuse cardinal slopes, apical angle about 
105°. Sides nearly parallel, spreading slightly toward the front, anterior 
angles obtusely rounded, and haying the front, for half its length, straight. 
The surface of the valves for nearly one-quarter of their width, on each 
side, is flattened —concave. 
The ventral valve has a broad rounded ridge along the middle, which 
descends at four-fifths from the front of the valve, somewhat abruptly, to 
the front edge ; the lateral thirds are concave, especially toward the beak, 
and the posterior edges of the valve are bent down or involute ; apex 
bluntly rounded. 
Some features of the interior appear on the abraded surface of the 
ralve examined. Two widely diverging ridges spread from the umbo 
toward the lateral edges, their ends being more than half way to the 
front of the valve, and about one-eighth of the width of the valve from 
its edge. About midway of the valve a rhombic area is outlined, at the 
front of which, on each side, would be the place of the anterior adductor 
muscles. 
The dorsal valve has the same outline as the ventral, but the edges of 
its posterior slopes are revolute, forming a channel on the outside of the 
shell at its back. The raised central part of the valve is wider in front 
than that part of the ventral valve. 
An abraded example of this valve shows imperfect traces of the pits 
of the posterior adductor and of the lateral muscles, and an imperfect 
outline of the visceral cavity. 
Sculpture—Only small fragments of the outer surface of the shell 
have been preserved ; these show that the surface was ornamented with 
numerous concentric, rounded ridges ; and under a strong lens the surface 
appears to be minutely granular, 
Size —Length, 35 mm.; width, 22 mm. 
Locality—Micaceous gray sandstones of Kelly’s Island, Conception 
Bay, Newfoundland, in company with Lingula Billingsiana, Whiteaves. 
This shell changed its form considerably during growth. When it 
attained the size of 8x11 mm. it was of a regular oval form, like Z. 
Quebecensis and several others of its genus, but then began to grow quad- 
rate. When three-quarters of its full length it was more rectangular than 
L. quadrata, and continued to grow more quadrate until it reached 
maturity. ; 
We know of no Cambrian Lingula to which this Newfoundland 
