BRACHIOPODA. 317 



.SUPPLEMENTARY NOTE ON VITULINA. 



(See i)i>. i:iS-!41.) 



Since the printing of the pages of this Volume, embracing the spire-bearing 

 brachiopods, attention has been directed by Professor II. S. Williams to the 

 fact that the presence of calcified brachial supports in Vitulina was noted by 

 him in his address before Section E of the American Association for the 

 Advancement of Science, in 1892. (See American Geologist, volume x. No. 3, 

 page 165. 1892.) The language used in this place is as follows : 



"The most striking evidence of the affinity of these several faunas was derived 

 from the study of three rather abundant genera of brachiopods ; Leptocalia, 

 Vitulina and Tropidoleptus, genera which I would describe as old-type genera for 

 this Devonian period, i. e., preserving the form and general characteristics of 

 the lower Silurian OrthidcR and StrophomenidcR, but assuming the later character 

 of calcified brachial supports of the Terebratulas and Spiriferidce. This is the 

 case for at least the first two genera, and Tropidoleptus possesses the punctate 

 structure characteristic of the Terebratulas." 



If it was the author's intention to intimate, in these sentences, that Vitulina 

 is possessed of calcified spirals, his meaning has been most successfully veiled, 

 and the reader might quite as fairly infer that the genus was regarded as 

 bearing a loop. Professor Williams has, however, kindly communicated some 

 further details of this structure accompanied by a figure, drawn from memory, 

 showing a multispiral cone directed toward the cardinal angle, and an elongate 

 loop showing " what appeared evidence of a saddle and accessory lamella as 

 in Athyris." The cones are actually paucispiral and directed toward the lateral 

 slopes of the pedicle-valve, but as to the structure of the loop our specimen has 

 furnished no satisfactory evidence. The presence of a highly developed saddle 

 and accessory lamellae would be surprising if true, and indeed quite incongru- 

 ous with our present knowledge of related genera. 



December, 1893. 



