NO. 1395. CAMBRIAN BRACHIOPODA—WALCOTT. 303 



ACROTRETA UPLANDICA LIMONENSIS Wiman. 



Acrotrela uplandka Umoneni^ia Wi.max, Bull. Geol. Institute, U]>sala, No. 2, YI, 

 1903, Pt. 1; Studien Nordbaltische Silurgebiet, p. 54, pi. ii, tigs. 19-22. 



Doctor Wiman states that this species is quite like A. uplandlca^ 

 hut lower, as the heio-ht is only one-third of the diameter. It is so 

 close in all other respects that I do not think that more than a varietal 

 value should be given to the ditierences mentioned. 



Forinatwn and Jocrdity. — Middle ? Cambrian. Bluish calcaneous 

 sandstone. Drift bowlder, Limon Island, Gefle Bay, Sweden. 



ACROTHYRA MINOR, new species. 



This species diti'ers from others referred to the genus by its broad 

 form and very strong- vascular sinuses. The elevated callus between 

 the sinuses is high and oval in outline, somewhat like that of Acrotreta 

 inflata. It ma}" be that this species l)elongs to a different genus, but 

 with the material available for study it is referred to Acrothyra on 

 account of its low, overhanging false area and elongate visceral area. 



Foi'inatlon (Old locality. — Middle Cambrian. Two miles southeast 

 of Malad City, Idaho. 



ACROTHELE (?) MINUTA, new species. 



Shell minute, 1.5 mm. in diameter, subcinadar in outline, gently 

 convex, with a slight median depression from the uml)o to the anterior 

 margin; back of the uml)0 there is a sharp median depression between 

 minute ridges, on each of wdiich there are two points or nipples. 

 Surface marked by line concentric stride. Substance of shell appar- 

 ently phosphatic. 



This interesting little species is represented by a single specimen. 

 The generic reference is somew^hat doubtful. 



Fonnathni aad locality. — Middle Cambrian. Chang' Hsia limestone. 

 Two and one-half miles southwest of Yen Chuang, Shantung, China. 



Collection of Eliot Blackwelder, Carnegie Institution of Washing- 

 ton, expedition to China. 



ACROTHELE RARUS, new species. 



Of this shell only the interiors of the valves are known. Shells of 

 average size are about 3.5 mm. in diameter. The outline of the valve 

 is subcircular, the transverse diameter being slightly more than the 

 length of the valve. The interior of the ventral valve shows that the 

 valve was moderately convex with a perforated apex about one-half a 

 millimeter from the posteric r margin. A short, broad median ridge 

 extends for a short distance in front of the foramina! opening and 

 short, narrow ridges extend obliquely forward from each side of the 

 opening. What may be lateral muscle scars occur close to the postero- 

 lateral margins. In the dorsal valve a strong median ridge extends 



