BRACHIOPODA. 469 



BpteUerideK] 



Z, uphami is the transitional species between Z. recurvirostra and Z. erratica 

 Hall,* and Z. headi Billings and its varieties borealis and anticostiensis.-\ Its nearest 

 relations are with Z. erratica. from which it differs in being narrower, of smaller 

 size, less quadrate in outline and without a sinus near the anterior margin of the 

 ventral valve. Z. headi is a large, elongate species, more strongly biconvex, with 

 the sinus of the dorsal valve far less conspicuous; var. borealis differs at once in its 

 greater length and tumid umbo; var. anticostiensis has a more swollen umbo and its 

 point of greatest convexity is near the mid-length, while in Z. uphami it is close to 

 the posterior margin. The latter also has a shallow, rapidly expanding mesial 

 sinus, which is obsolete or not present in var. anticostiensis. Named in honor of 

 Mr. Warren Upham, of Somerville, Mass., for several years an assistant on the 

 Minnesota survey. 



Formation and locality. This species seems to be abundant, but is restricted to beds only a few feet 

 in thickness, near the middle of the Galena horizon at Weisebach's dam near Spring Valley, and neat 

 Wykoff and Fountain, Minnesota; also in equivalent position in Goodhue county. 



Collectors. W. H. Scofleld, E. O. Ulrich and C. Schuchert. Also in the collection of Dr. C. H. 

 Bobbins, Wykoff, Minnesota. 



Mus. Reg. Nos. 8227. 



Family SPIRIFERID^], King. 



Subfamily S.UESSIIN^E, Waagen. 



Genus CYCLOSPIRA.it 



The important diagnostic character of Cyclospira is the nature of the calcified 

 brachial supports. The primary lamellae are straight at their point of origin from 

 the crura, thence continuing anteriorly nearly parallel to each other, and recurving 

 somewhat laterally. The Minnesota example in which the brachial supports have 

 been developed does not show a complete revolution of the primary lamellae, but in 

 a specimen from New York, developed by Mr. John M. Clarke, there are about two 

 and one-half turns to the spiral. This specimen also shows that the second and 

 third turns are somewhat medially directed or introverted. There appears to be a 

 complete loop joining the primary lamellae near their point of origin with the erura 

 in the Minnesota example, but in the New York example the loop appears to be 

 represented by two prongs or remnants of a loop, as in Spirifer. These differences, 

 if correctly ascertained, should be regarded as of generic value; but, since the shells 

 from the two localities are alike exteriorly, we believe that when more material from 

 Minnesota is investigated they will prove to be structurally in harmony with the 

 eastern specimens. 



*Ortftte erratiea Hall. Pal. N. Y., vol. i, p. 288, pi. LXXIX, (igs. 5a-5f, 1847. 

 + Pal. Foss., vol. 1, p. 14T, figs. 125-127, 1862T. 



tThe generic description of this genus will be published In Pal. N. Y., vol. viil, pt. 11. The type species is Ort/iis 

 bisulcata Emmons. 



