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“ Spirigera must include those with the beak of the ventral valve per- 
forated, and a rudimentary mesial septum in the dorsal valve (type S. 
concentrica).” 
The writer here seems to have fallen into the same error as before re- 
ing ATHYRISs, which he says has A. tumida as its type.* The type of 
THYRIS 1s A. concentrica ; and A. tumida of Dalman was, ten years 
Bie If the reader will take the trouble to compare this sentence with the three pre- 
the of paragraphs, he will perceive that Prof. Hall misunderstands or misin 
the original statement. The reviewer does not aver that A. tumida is the type of 
genus Atarris, but that it is the type of “a group of species of Ararris. 
Benus as originall ized by McCoy is osed of:eer 
ie 
Rae da is the central and typical form. i 
thal order to show that the position taken by the reviewer is the correct one, we 
 ashort history of the facts, ‘ : 
had a was the first to point out that certain species of Brachiopoda which 
‘ccount of their possessing i bed Lenival 2 a 
“Atiris, McCoy (fp. To), in which there te no vestige of either foramen, 
“ line. (fig. 19), in — there is no vestige forypre 
o the pe and refers 
same page he figures a species (but without a specific name) to 
me 19) as an inate of his tea of the typical form of his genus. . shows 
in the He does not point out any particular species by name 
ae of his genus. The first cputian? described by him he refers to A. con- 
in this he was probably mistaken. His description is not that of 4. 
Centrica, 
coneentrica, and further 
respecti: g : including ash 
and ve types? All his writings on the 
Well infos Pt to quote his opinions otherwise will be suce n 
oe paleontologist to the . His’ only mistake was in supposing 
JouR. Sc.—Srcoxp Series, Vor. XXXII, No. 97.—Jas., 1 
17 
