NO. 1299. CAMBRIAN BRACHIOPODA—WALCOTT. 595 



The varieties tacoidca and transversa are strongly marked. Inxt I 

 think are not entitled to full specific valuation. 



A direct comparison of specimens from the black shales of Little 

 Metis with those from the black shales of the type locality of A. sa(j!t- 

 taJis at St. Davids fails to disclose any specific difi'erences ])etween 

 them, as far as the material at hand permits of comparison. The 

 Little Metis shell was identified with '^ Oholella-Acrothele^'' jpretlosa by 

 Prof. James Hall, and this identification was accepted by Sir William 

 Dawson. '^ Oholelhr^ pretiosa is a true Acrothele, and no species of 

 Acrotreta is known to occur at the type locality on the Chaudiere 

 River. The stratigraphic horizon of the Little Metis beds has not been 

 definitely determined. Sir William Dawson saj's, "At Metis the evi- 

 dence of the pebbles in the conglomerates indicates that they are newer 

 than the Lower (Jambrian, and the few fossils found in tke sandstones 

 and shales would tend to place them at or near the base of the Levis 

 division, or approximately on the horizon of the Chazy.^ I personally 

 examined the section at Little Metis in 1899, and am not at all certain 

 of the horizon of the shales carr3nng Acrotreta sagtttalis and the 

 beautiful fossil sponges described by Sir William Dawson. It is a 

 region of strong folding and thrust faults. The Acrotreta is a Middle 

 Cambrian type, and nothing similar to it is know n from the Upper 

 Cambrian. As far as this shell can locate the horizon it is Cam])rian, 

 and probably low down in the Upper Caml)rian. 



Formation and localities.— 'y^iiMlQ Cambrian, Paradoxides zone, 

 Menevian, St. Davids, South Wales; near Dolgelly, North Wales. 

 See Davidson for local distribution in the Menevian. Limestones of 

 Paradoxides fo7'chhanieri\)Q^s., Andrarum, Lovened Djupadalen Vester- 

 gotland, Sweden. Borregard Bornholm, Denmark. Limestone with 

 Paixidoxides davisi., Seal Point Cove, near Long Point, Trinity Bay, 

 Newfoundland. Black shales of Little Metis, Province of Quebec, 

 Canada, in association w4th fossil sponges described by Sir Willianr 

 Dawson. Probable horizon between the Middle and Upper Camlu'ian. 



ACROTRETA SAGITTALIS MAGNA Matthew. 



Linnarssonia belti Davidson niut. magna Matthew, Traiif^. Koy. Soc Canada, 2d 

 ser., Ill, 1897, p. 169, pi. i, figs, la, lb. 



In addition to the material collected by Dr. G. F. Matthew I have a 

 number of specimens collected b}^ me at the typical locality. A com- 

 parison with a series of specimens of A. sagittalis from St. Davids, 

 Wales, and of A. sagittalis transversa, shows at once that the form Dr. 

 Matthew named is very closely related to both. The length and size of 

 the median ridge, the position of the central scars of the brachial 

 valve, and the size and position of the cardinal scars of the j^edicle 

 valve are the internal characters that Dr. Matthew depends upon to 



1 Trans roy. l= Canada, VII, 1889, p. 32. 



