NO. 2144. NEW BRACHIOPODS FROM MAINE— WILLIAMS. 77 



The two species together {/S. t^^escottl and S. cohscooM) fairly 

 well represent the characters generally ascribed to Dalman's species 

 Delthyris elevata, but the first, with a median septum in the pedicle 

 valve, lacks the groove in middle of the brachial fold, and the second, 

 having the groove, lacks the median septum. Until further light is 

 thrown on the matter the three species may be regarded as distinct 

 though very closely related. 



Formation. — Edmunds formation of the Silurian. 



Locality. — South of Bells Mountain, on west shore of Cobscook 

 Eiver, Edmunds Township, Washington County, Maine. 



Holotype and paratypes. — Cat. No. 61452, U.S.N.M. 



SPIRIFER EDMUNDSI Williams. 



Plate 1, figs. 13, 14, 15. 



1905. Spirifer cf. perlameUosus Hall, Williams, Prof. Paper U. S. Geol. 

 Surv. No. 35, pp. 22, 28. 



Specimens described under the name Spirifer edmundsi differ 

 from S. cohscooki in the following particulars: They are larger in 

 size, have a greater number of plications (6 and 7 instead of 4 and 

 5, respectively, on each side of the brachial and pedicle valves), a 

 lower area, and more angular cardinal extremities. The two species 

 agree in lacking a median septum in the pedicle valve and in possess- 

 ing a groove in the middle of the brachial fold. 



Spirifer edmundsi closely resembles some figures of Hall's species 

 S. perla/inellosus., as w^ill be seen upon comparing our figures 13, 14, 

 15 on plate 1 with Hall's figures on plate 2G.^ 



The type-specimen (pi. 1, fig. 13) was about 28 mm. from tip to 

 tip of cardinal margin. The corner on the left is broken off in the 

 specimen. Hall's figure Ig of S. perlameUosus measures 27 mm., 

 and the several figures given on his plate 26 vary from 10 to 45 mm. 



The cardinal extremities of our specimen are closely similar to 

 those of Hall's figure In. The plications on right side of figure 13 

 are 7 ; those on Hall's figure l/i are 6 on left and 5 on right side. 



The brachial valve (pi. 1, fig. 14) shows 6 plications on the right 

 of the fold ; Hall's figure Ip shows 6 plications each side the median 

 fold. The surface markings are similar in the two species. The 

 area is flat and extended as in Hall's figure Im. 



Spirifer edmundsi differs from S. perlarrheTlosus in the possession 

 of a well-defined groove along the middle of the brachial fold from 

 beak to front of the shell and in the absence of any trace of median 

 septum in the pedicle valve, which is present in S. perlameUosus. 



Formation. — Edmunds formation of the Silurian. 



Locality. — South of Bells Mountain, on the west shore of Cobscook 

 Eiver, Edmunds Township, Washington County, Maine. 



1 Paleontology of New York, vol, 3, pi. 26. 



