Notes on Spirifera Parryana. 21 



XIII, Fig. 8 a-c, Meek and Worthen described a specimen of 

 Spirifera parryana under the name Spiri/er fornaaila^ Hall. 

 A young, medium sized individual, with the shell partly ex- 

 foliated, was chosen for illustration. The hinge is perhaps a 

 little longer than in the average 5. parryana, but the form is 

 by no means unusual in collections embracing representative 

 series of this species. 



Two of Meek and Worthen's figures are copied under the 

 erroneous name, Spiri/er fornacula, in Le Conte's Elements 

 of Geology, Fig. 391 a. b. 



Spirifera fornacula is a name applied by Hall to a small 

 species said to have been obtained from Devonian limestone at 

 Bake Oven, Illinois. The description was pubHshed without 

 illustrations in the Tenth Report on the State Cabinet of New 

 York. Very few species so published can be identified with 

 certainty even by expert palaeontologists, and so an exfoliated 

 S. parryana from the Bake Oven was referred as above de- 

 scribed, but with grave doubts on the part of the authors, to 

 S. fornacula. The form which had been described in the 

 Tenth Report, State Cab. N. Y. as 5. fornacula, was after- 

 ward figured and described in Palaeontology of New York, 

 Vol. IV, p. 211, Plate XXXI, Fig. 11, 12, 13, as Spirifera 

 euruteines var. fornacula. By means of the excellent figures 

 given we are now able to appreciate the characters of the 

 form so designated. The species is certainly very distinct 

 from S. parryana. The shell is smaller and of different pro- 

 portions. The plications, the hinge area, and the mesial fold 

 and sinus present characteristic differences. 



There is one reference to Spirifera parryatia in Hall's 

 Geology of Iowa, Vol. I, Part 2, p. 512, that I confess I do 

 not understand. After mentioning " the narrow linear area, 

 mucronate cardinal extremities, shallow sinus and slight mesial 

 elevation, which are covered by dichotomizing plications," 

 as characters distinguishing Spirfer inarionensis, Shumard, 

 the author proceeds to say that '■'■Spirifer parryanus simulates 

 this one in its dichotomizing plications on the mesial fold and 



