NEW SPECIES OF CAMBRIAN FOSSILS FROM CAPE BRETON. 
273 
the great muscle, which with more probability may be considered the 
external lateral or “1” muscle ; the large oval muscle would then be 
the “ h ” central (with possibly the “ k ” lateral involved), but it 
would consist of three main strands ; for beside the septum across the 
middle at the back, the scar is divided bv a more obscure transverse 
ridge parallel to the long diameter of the scar. This muscle then may 
be compared to those of Lingula, etc., having divisional lines.* 
In 0. (L.) ccdatus , Volb., we see an arrangement of muscle scars 
in the central group of the ventral valves similar to that in L. (?) 
Escasoni.j Here Mr. Walcott interprets the small scar as an external 
lateral (“ 1 ”), but the larger one as a middle lateral (“k”). Vol- 
booth’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 Euo bolus.” ; 
Lingulella concinna, n. sp. PI. V, fig. 2 a-b. 
Occurring in the dark gray shales of the Upper Cambrian on 
McLeod Brook are a few examples of a small Lingulella smoother than 
a species from the same beds referred provisionally to L. lapis , but 
ornamented, as that species is by concentric ridges. 
The shell substance is quite thin towards the lateral and front 
margins, and is then flattened out by pressure. The beak is somewhat 
blunt, and the rounded lateral margins give the ventral valve an ovate 
form. 
Sculpture. — Over the visceral space the surface of the valves is 
covered with very fine concentric somewhat lamellose ridges, visible 
with a lense ; over the branchial area these ridges flatten down, and 
the valve has a shining granular surface ; the ridges, however, remain 
distinct on the lateral margins, though there also the surface is bright. 
Size . — Length of the ventral valve, 8 mm.; width, 6 mm. The 
dorsal valve is nearly 1 mm. shorter than the ventral. 
Horizon and locality . — In the fine dark grey shales of Div. 3c, at 
McLeod Brook, Boisdale, N. B. Scarce. 
introduction to study of Brachiopoda, Hall & Clarke, p. 229 ; fig. 23, and pi. 2, fig. 5. 
t U. S. Nat. Mus. Proc. Vol. XXI., p, 385, PI. xxvi., fig. 1. 
t Imp. Acad. des. Sci , St Petersbourg. Ser. VlII., Tom. iv.. No. 2. PI. II., figs. 19c 
and 2 c 
