608 CAMBRIAN BEACHIOPODA. 



the anterior and lateral portion of the valves. The interior layers and interior surface show 

 numerous fine, radiating striae, and there are also a few radiating lines on the anterior portion 

 of the adult shells. 



The shell is built up of a thin outer layer and numerous inner layers or lamellae that are 

 oblique to the outer surface; the oblique layers on the front portion and sides of adult shells 

 terminate at the growth lines, so as to give an imbricated appearance to the surface. Shell 

 substance apparently corneous. 



A large ventral valve has a length and breadth of 11.5 mm. A dorsal valve 10 mm. long 

 has a width of 12 mm. These proportions vary slightly in different shells. 



The interior of the adult ventral valve is much like that of Botsfordia cselata (Hall). It 

 has a short visceral area between distinctly marked main vascular sinuses that originate one 

 on each side of the median line at the posterior margin, and gradually separate as they extend 

 forward into the valve; no distinct muscle scars have been seen in this valve. The interior 

 of the dorsal valve has a long central ridge extending well toward the front of the valve; at 

 about the center it shows a tendency to bifurcate; the main vascular sinuses originate at the 

 median line near the posterior margin and arch rapidly outward on each side and then obliquely 

 forward into the body of the valve; the muscle scars are represented by an elongate cardinal 

 scar on each side near the main vascular sinus, where it curves forward into the valve; also 

 one central muscle scar on each side of the median ridge a little back of the center of the valve. 



Under the description of the genus Botsfordia I have referred (p. 602) to the description of 

 the interior of this species by Matthew. I have given above all I can observe on the specimens 

 in the Matthew collection now at the University of Toronto, also on the specimens in the col- 

 'lection of the United States National Museum. 



Observations. — This species is so clearly distinct from Botsfordia cselata (Hall) and B. gran- 

 ulata (Redlich) that comparison is unnecessary. It agrees with both of the latter species in 

 having the perforated apex of the ventral valve separated from the posterior margin by a 

 narrow rim of shell, also in having a short visceral area and strong main vascular sinuses. The 

 dorsal valves are of the same general type. 



Formation and locality. — Middle Cambrian: (2y) Sandstone about 25 feet (7.6 m.) above the Lower Cambrian, 

 on the southeast side of Catons Island; and (308d [Matthew, 1894, P- 1^1]) sandstones of Division Clb2-4 of Matthew's 

 section on Catons Island; both in Long Reach, St. John River, Kings County, New Brunswick. 



Genus SCHIZOPHOLIS Waagen. 



[nKiu, I divide; and ^>.ic, a scale.] 

 Schkopholis Waagen, 1885, Mem. Geol. Survey India, Paleontologia Indica, 13th eer.. Salt Range Fossils, vol. 1, 



pt. 1, p. 752. (Described as a new genus.) 

 Schizopholis Waagen, Oehlbet, 1887, Manuel de conchyliologie, by Fischer, p. 1267. (Described in French, with 



figures of S. rugosa.) 

 Schizopholis Waagen, Hall and Clarke, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 248. (De- 

 scribed.) 

 Schizopholis Waagen, Hall and Clarke, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, p. 564. (Copy 



of preceding reference.) 

 Schizopholis Waagen, Hall and Clarke, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 94. (Copies original 



description and discusses genus.) 

 Schizopholis Waagen, Walcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, PI. XI, and pp. 142 and 145. (Classi- 

 fication of genus.) 



Revised generic description. — Ventral valve slightly conical with eccentric apex perforated 

 on the posterior side by a minute foramen. On the posterior slope beneath the apex there 

 is a slightly flattened false area across which the strise of growth of the shell appear. The 

 striee arch upward near the center and form a narrow false deltidium, very much as in the 

 genera AcrotJiele and Acrotreta. The pedicle opening occurs at the apex of the false deltidium 

 and penetrates the apex of the shell. Dorsal valve nearly fiat, umbo slightly elevated, beak 

 marginal. 



Surface of shell marked by fine concentric lines and strise of growth, and irregular, inter- 

 rupted, slightly elevated, radiating ridges which give a rugose appearance to the surface. Shell 

 substance calcareocorneous. Shell built up of several layers or lamellae. 



