692 CAMBRIAN BRACHIOPODA. 



^ ACEOTEETA KUTOEGAI Walcott. 



Text figure 58; Plate LXV, figures 3, 3a-e, 3g-k. 



Acrotreta kutorgai Walcott (in part), 1902, Proc. U. S. Nat. Mus., vol. 25, pp. 589-590. (Described as a new species, 

 but owing to a different interpretation of the structural characters of the ventral valve the description differs 

 from the one given below. Specimens now referred to Acrotreta rudis were included with true representatives 

 of A. kutorgai in this description.) 



The external characters of the ventral valve ai^e clearly exhibited (PI. LXV) by figures 

 3, 3a, and 3d, and what is known of the interior by figures 3b and 3c. Figure 3g is that of a 

 most interesting specimen, as it clearly shows the cast of the cardinal area of the dorsal valve 

 adjusted against the false area and pseudodeltidium of the ventral valve. In 1902 (p. 589) 

 I considered this cast of the cardinal area of the dorsal valve to be the true area and pseudo- 

 deltidium of the ventral valve, and figure 3g was drawn to bring out this interpretation. 



Figure 58 represents a view into the interior of the cast, showing the cast of the false area 

 and pseudodeltidium of the ventral valve, as well as the cast of the cardinal area of the dorsal 



valve. The cardinal area of the dorsal valve is well 

 defined in the casts represented by Plate LXV, figures 

 3h-j. The median ridge of the dorsal valve is as long 

 proportionally as that of A. hisecta, and like it varies in 

 length and size in different shells. 



The outer surface is marked by fine concentric strise 

 and lines of growth. 



Observations. — This pretty species occurs attached 

 to the surface of siliceous nodules in association with 



Figure S&.-Acrotreta Icuforgai Walcott. View into QlenoideS CUHicei, CrepicBphaluS texaUUS, AcTOtheU lellula 

 interior, the specimen being tipped, as shown in the i- ■» r i mi i- 



side outline. A vertical view of the same specimen Walcott, and CastS Ot AlcduSffi. ihe OutimC ot the COn- 



is sho^vn in Plate LXV, flgwre 3g. vcxity of the valvcs and tlie posterior view of the ventral 



c.:^Z::'Z:Z^^^:Z^::^.^. ^^l^e is most hke t\.^t oi a. attenuata Meek, but the 



^ interior markings are quite unlike. 



The specific name was given in honor of Kutorga. 



Formation and locality. — Upper Cambrian: (361) Shaly limestone in suburb of Attalla, Etowah County, 

 Alabama. 



(107o and 107u) Limestones and shales at the base of the Knox dolomite, west of the top of Copper Ridge, near 

 the Southern Railway cut, about 10 miles (16.1 km.) northwest of Knoxville [Keith, 1896b, areal geology sheet], 

 Knox County, Tennessee. 



Middle Cambrian: (90b) Conasauga limestone in cut on Louisville and Nashville Railroad, near Woodstock, 

 Bibb County; (90) Conasauga ("Coosa") shale on Edwards farm, near Craigs Mountain, about 10 miles (16.1 km.) 

 southeast of Center, Cherokee County; (140) limestone interbedded in shales near Chepultepec, Blount County; 

 (90x) in and attached to the outer surface of siliceous nodules in the Conasauga (" Coosa") shale, Coosa Valley, Cherokee 

 County; (137) shales on the southeast side of the northeast end of the Cane Creek Mountains, 3 miles (4.8 km.) south 

 of Gadsden, Etowah County; and (139a) limestones on road near Wades Gap, near Chepultepec, Blount County; all 

 in Alabama. 



Specimens that are somewhat doubtfully referred to this species occur at the following 

 localities : 



Middle Cambrian: (142) Shales just above the Olenellus zone, near the railroad, 4.5 miles (7.2 km.) north of 

 Montevallo, Shelby County, Alabama. 



(18) Limestone 1 mile (1.6 km.) east of Gap Creek, 13 miles (20.8 km.) S. 75° E. of Knoxville, Knox County, 

 Tennessee. 



ACEOTRETA LISANI Walcott. 



^y 



Plate LXVIII, figures 3, 3a-c. 



Acrotreta Hani Walcott, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 300. (Described and discussed as below as a new 

 species. Li San's name was at that time believed to be correctly written as Lian, hence the form of the 

 specific name.) 



Shell small, about L5 mm. in diameter; outline of aperture subcircular, the posterior 

 side being slightly transverse. Ventral valve conical, with the apex a little in advance of 



