BRACHIOPODA. 
319 
Genus AULOSTEGES, von Helmersen. 1847. 
PLATE XVII, PIGS. 47-49. 
1845. Orthis, de Vernecil. G6ol. Russ. d’Europe et des Mont. l’Oural, vol. ii, p. 198, pi. xi, fig. 5. 
1847. Anlosteges, ton Helmersen. Neues Jahrb. fur Mineral., p. 330. 
1847. Aulosteges, von Helmersen. Bull. Acad. Imp. Sci. St. Petersbourg, vol. vi, p. 135, pi. vi, fig. 12. 
1850. (?) Strophalosia, King. Monogr. Permian Fossils England, p. 93. 
1853. Aulosteges, Davidson. Introd. British Fossil Brachiopoda, p. 116, pi. ix, figs. 212-216. 
1848. Aulosteges, Shumard. Trans. St. Louis Acad. Science, vol. i, p. 292, pi. xi, fig. 5. 
1861. Strophalosia, Geinitz. Dyas, Heft i, p. 93. 
1862. Aulosteges, Davidson. Quarterly Journal Geological Society, vol. xviii, p. 33, pi. ii, fig. 7. 
1863. Aulosteges, de Koninck. Fossiles pa!6ozoiques de l’lnde, p. 41, pi. xii, fig. 7. 
1S83. Aulosteges, Hall. Ann. Rept. 1ST. Y. State Geologist for 1882, pi. (xvii) 48, figs. 47-49. 
1884. Aulosteges, Waagen. Palaeontologia Indica; Salt-Range Fossils, vol. i, pt. iv, p. 661, pi. lxii, 
figs. 1-4 ; pi. lxiii, fig. 1. 
Diagnosis. Shell productiform in general aspect, somewhat depressed, not 
attached. On the pedicle-valve the cardinal area is prominently developed, 
frequently somewhat distorted; the delthyrium is closed by a convex deltidium 
which is covered with little tubercles or spinules. Cardinal teeth rudimentary 
or absent. In the brachial valve the cardinal area is linear, the cardinal process 
large, quadrifid; its base being surrounded by a strong deltidial callosity. Bra¬ 
chial ridges extending nearly to the anterior margin and abruptly incurving. 
Otherwise the interior impressions are as in Productus. Surface of both valves 
thickly set with spines. 
Type, Aulosteges variabilis , von Helmersen, = Orthis Wangenheimi, de Verneuil. 
Permian of Russia. 
Observations. It was early observed by King that Aulosteges formed a 
connecting link between Strophalosia and Productus. The constant presence 
of the cardinal area and the usual absence of the hinge-teeth, show the correct¬ 
ness of this observation as far as it bears upon the structure of these genera. 
Aulosteges is chiefly if not wholly of Permian age, and it may perhaps be better 
to regard it as a descendant or offshoot from Strophalosia ; showing the obso¬ 
lescence of teeth, which is the tendency toward the prevailing brachiopod type 
of that and the preceding fauna. The specific representation of Aulosteges 
is quite meager. The original species, A. Wangenheimi , de Yerneuil (which, 
according to King, Davidson and others, is identical with, and therefore has 
