ORGANISMS IN ACADIA, 1S5 



favoxa, Liurs, of the Fiicoidal saudsloue in Sweden ; but in that shell the sides meet 

 behind at an angle of 90°, and the shell is said to be pitted. Another resembling species is 

 LingideUa caiata, Hall, of the Olenellus beds of New York ; and a third is Kidorgina 

 pannula, White, of the Nevada Cambrian rocks, but both are much smaller, and in these 

 two species the cancellated markings cover the whole surface. 



Obolus (?) MAJOR, n. sp. (Plato VIII, fig. 3.) 



Only the dorsal valve known. This is transversely oval, flattened near the umbo, 

 and deep within the edges toward the back of the shell. 



The interior markings seem those of an Obolus. The mosiau line is strongly marked 

 just within the umbo, and at the middle of the shell, in front of which it appears to fork. 

 The scars of the posterior laterals only are distinct. 



The example known shows the interior of the shell and a little of the external sur- 

 face. The shell was thin, and is changed to iron-oxide. The outer surface near the edge 

 of the shell was covered by fine radiating lines or ridges. 



A trace of the beak of the ventral valve is preserved and is indicated by a dotted line 

 in the figure. 



Horizon and Locality. — In the sandy shales of Series A, (Basal series) Div. 2 h. 



This species is found in beds which are nearly or cjuite equivalent in age to the 

 Eophyton sandstone of Sweden, from which, in 1869, Liunarsson described Lingula (?) 

 monilifera} "With this species I should be inclined to identify ours, although it is larger 

 and wider, for it has a similar ornamentation ; but further developments regarding the 

 form of the interior of Lingtda (?) monilifera based on numerous examples found by the 

 Russian engineer Mickwitz, near St. Petersburgh, and described by Dr. F. Schmidt, show 

 it to be an entirely different shell. Dr. Schmidt finds in the interior of the dorsal valve 

 an extraordinary horn, rising from its centre and directed into the beak of the ventral 

 valve. The existence of such a structure certainly is not indicated in the Acadian species 

 above described, the interior of which resembles that of the genus Obolus. We have, 

 therefore, felt compelled to refer it provisionally to that genus under a new name. It 

 will be observed however, that our species possesses the peculiar flattening of the dorsal 

 valve, so remarkably exhibited in Mickioitzia monilifera. 



LINGULELLA, SaUer, 1861. 



LiNGULELLA Martinensis, u. sp. (Plate VIII, fig. 4.) 



Orbicular, ovate, broadly rounded in front, somewhat ventricose. Beakof the ventral 

 valve prominent. No other sculpture than that of concentric and radiating striae has 

 been observed. 



Size. — Length of ventral valve, about 10 mm. ; width, about 8 mm. 



' See also Geol. Mag. London, 1868, p. 398, tab. xi, figs. 1 and 2, and Geognostiska ocli Palieontologiska 

 iakttagelser ofver Eophyton sandston, Stockholm, 1871, J. G. O. Linnarsson, where it is called Obolus (?) monilifera. 



