110 
PALAEONTOLOGY OF NEW YORK. 
Genus SIPHONOTRET A, de Verneuil. 1845. 
PLATE IV, FIGS. 24-26, 37, 38. 
1829. Crania, Eichwald. Zoologia specialis, vol. i, p. 274. 
1840. Terebratula, Eichwald. Ueber das siluriscb. j Schichten-Syst. von Esthland; Journ. Nat. Heil- 
kund. med.-chirurg. Acad. St. Petersb., p. 138. 
1842. Terebratula, Eichwald. Die Urwelt Russlands, Heft 2, p. 145. 
1845 SipJionotreta, de Verneuil. In Murchison, de Verneuil and Keyserling’s Geol. de la Russie 
d’Europe etdes mont. de l’Oural, p. 286, pi. i, figs. 13, 14. 
1848. /SipJionotreta (partim), Kutorga. Ueber die Brachiopoden-Pamilie der Siphonotretsese; Ver- 
handl. russ.-kais. mineral. Gesellsch. zu St. Petersburg, p. 261, pis. 
vi, vii. 
1849. SipJionotreta, Mokkis. . Annals of Natural History, Ser. 2, vol. iv, p. 315. 
1853. SipJionotreta, Davidson. Introd. British Fossil Brachiopoda, p. 131, pi. ix, figs. 261-270 (not 268). 
1866. SipJionotreta, Davidson. British Silurian Brachiopoda, p. 75, pi viii, figs. 1-6. 
1871. SipJionotreta (partim), Quenstedt. Petrefaktenkunde Deutschlands; Brachiopoden, p.674, pi.61. 
1877. SipJionotreta, Davidson. Geological Magazine, p. 13. 
1883. SipJionotreta, Davidson. British Silurian Brachiopoda, Suppl., p. 217, pi. xvi, figs. 31-33. 
Diagnosis. Shell elongate-oval, inequivalve ; valves inarticulated. Pedicle- 
valve the more convex, with a straight, elevated, conical, and perforated beak, 
the circular foramen opening at the apex and communicating with the interior 
of the shell by a tubular canal, which narrows slightly as it passes inward. No 
cardinal area or deltidiuin is present, the growth-lines passing between the beak 
and the posterior margin as elsewhere on the shell. Brachial valve depressed- 
convex ; beak marginal; posterior margin regularly arched and thickened. 
Interior of pedicle-valve with muscular impressions confined to the umbonal 
region. Close alongside the opening of the sipho, just within the cardinal 
margin, lie two elongate scars which are accompanied on either side by broader, 
somewhat expanded or flabellate, simple and less distinct impressions. Directly 
in front of the middle pair lies a small central scar, in the axis of the shell, 
and at either side of it a transversely elongate impression. These latter im¬ 
pressions are distinctly separated from the former by a transverse ridge. 
In the brachial valve the impressions are equally concentrated, the entire 
muscular area being bounded on its posterior margin by a prominent ridge 
which, at the sides, merges into a compound lateral scar. The central portion 
of the area is much depressed and is divided axially by a narrow ridge or 
septum. 
