320 
PALAEONTOLOGY OF NEW YORK. 
priority over von Helmersen’s A. variabilis ), is from the Permian of northern 
Russia. Davidson recognized no species in the British formations, though King, 
in 1856, # considered his Productus umbonillatus (=P. latirostratus, Howse) an 
Aulosteges. Davidson described A. Dalhousii, and Waagen A. Medlicottianus, 
from the Permian of the Salt-Range of India. In America but two species 
have been referred to this genus, namely, A. Guadalupensis, G. C. Shumard, from 
the Guadalupe Mountains of Texas, a very imperfect shell, insufficiently illus¬ 
trated, but showing a high cardinal area; and A. spondyliformis , White and St. 
John, from the Upper Carboniferous beds of Iowa; a form which it would be 
difficult to separate from Strophalosia on the basis of the features given in 
the original description and figures. 
Mr. R. Etheridge, Jr., in discussing “ Adherent Carboniferous Productidse,”f 
has figured (figs. 2-4) and described a shell which he regards as Chonetes, 
adherent by its spines (figs. 2, 3) and the outer surface of the pedicle-valve to 
foreign objects. This discussion is one of great interest and will be referred to 
at greater length in regard to some important points established in this and a 
previous paper on the same subject, by Mr. Etheridge. There is some room for 
doubt, however, whether these shells should be regarded as belonging to the 
genus Chonetes. The individual represented in figure 4 of his work, a pedicle- 
valve with area and delthyrium, attached by its outer face, and covered with 
spines creeping over the surface of the host, can hardly be anything but a 
Strophalosia of the type of S. radicans, S. Keokuk and S. scintilla. The subject 
of the other figures, a shell in which one of the cardinal spines encircles a 
spine of Productus, is quite imperfect but has a more decided chonetiform ex¬ 
pression. It will be interesting to learn more of this peculiar form. 
* Annals and Mag-azine of Natural History, 
t Quarterly Journal Geological Society, vol. xxxiv, p. 498. 1878. 
