209 



In 0. (L.) ccelatus, Volb., we see an arrangement of muscle scars in 

 the central group of the ventral valves similar to that in L, (T) Escasoni* 

 Here Mr. Walcott interprets the small scar as an external lateral (!"), 

 but the larger one as a middle lateral ("k "). Volborth's figure of this 

 species does not show the small scar, but he appears to allude to it in the 

 text where he says that " the several laterals of the ventral valve are not 

 so closely bound together as in the subgenus Euobolus.f" 



LINNARSSONIA, Wale. 

 OBOLUS. 



An orbicular brachiopod (a single valve) was found in the flags of Div. An O!x>lus. 

 (C. 26.) on the east side of the Long Island passage. The material is not 

 sufficient to determine the species. 



LINNARSSONIA, cf. BKLTi, Davidson ? PL XVI. figs. 3a-c. 



Linnarssonia Belti, Dav. 1 Trans. Roy. Soc. Can. vol. ix, p. 42, pi. xii 



figs. 7a-c. 



The shell of the St. John Basin referred to this species, has the follow- 

 ing characters : 



Shell oblately orbicular. Test corneous. 



The dorsal valve (?) resembles that of the shell (0. misera ?) in the zone Linnarssonia 

 (C. Id) of the St. John Group, being like that of an Acrotreta in its in- cf ' Beltl> 

 ternal markings. 



In the ventral valve we do not see the strong scars and V-shaped ridge 

 at the umbo, of the typical forms of Linnarssonia, but in their place 

 small scars, and two faint V-shaped lines extending from the umbo. 



Sculpture. The surface of the shell is marked with fine concentric and 

 less distinct radiating lines, or is smooth. 



Size. Length 3 mm. ; width 3 mm. 



Horizon and locality. From fine gray shales of the Dictyonema beds 

 (Div. C. 3c) at Navy island, St. John harbour. 



This little shell is distinguished from those that occur with it (except 

 Acrotreta),' not only by its form, but also by the extreme t nuity of its 

 test, thickened only at the umbo. In this also it resembles the shell from 

 JDiv. (C. Id) referred to above, and those of the genus Acrotreta. 



* U. S. Nat. Mus. Proc. Vol. XXI., p. 385, PL xxvi., fig. 1. 



t Imp. Acad. des. Sci., St. Petersbourg. Ser. VIII. , Tom. iv., No. 2. PL II., figs. 

 19c and 2le. 



14 C. R. 



