110 PALEONTOLOGY OF NEW YORK. 



Genus SIPHONOTRETA, de Verneuil. 1845. 



PLATE IV, FIGS. 24-26, 37, 3S. 



1829. Crania, Eichwald. Zoologia sp'ecialis, vol. i, x>- 274. 



1840. Terehratula,'Eic\VNM,T>. Ueber das siluiiscli.,Schichten-Syst. von Esthland ; Journ. Nat. Heil- 



kund. niftd.-chii-urg-. Acad. St. Petersb., p. 138. 

 1842. Terehratula, Eichwald. Die Urwelt Russlands, Heft 2, p. 145. 

 1845 Siplionotreta, di5 Vekneuil. In Mui-chison, de Venieuil and Keyserling's Geol. de la Russie 



d'Eui'ope et des mont. de rOural, p. 286, pi. i, figs. 13, 14. 



1848. Siphonotreta (imrtim), Kotorba. Ueber die Brachiopoden-Familie der Siphonotretseae ; Ver- 



handl. I'uss.-kais. niinei'al. Gesellscli. zu St. Petersburg, p. 261, pis. 

 vi, vii. 



1849. Siyhonotreta, Monius. Annals of Natural History, Ser. 2, vol. iv, p. 31.5. 



1853. Siplionotreta, Davidson. IntroJ. Bi-itish Fossil Brachiopoda, p. 131, pi. ix, figs. 261-270 (not 268). 



1860. Siphonotreta, Davidson. Bi'itish Silurian Brachiopoda, p. 75, pi viii, figs. 1-6. 



1871. Si.phonotreta [partim), Quenstedt. Petrefaktenkunde Deutschlands ; Brachiopoden, p.674, pl.61. 



1877. Siplionotreta, Davidson. Geological Magazine, p. 13. 



1883. Siplionotreta, Davidson. British Silurian Brachiopoda, Suppl., p. 217, pi. x\'i, figs. 31-33. 



■ Diagnosis. Shell elongate-oval, inequivalve ; valves inarticulated. Pedicle- 

 N^alve 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 deltidium 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. 



