Mr. J. Morris on the genus Siphonotreta. 315 



XXXII. — Note on the genus Siphonotreta, with a description of a 

 new Species. By John Morris, F.G.S. 



[With a Plate.] 



Among the numerous interesting fossils collected by Mr. John 

 Gray from the Wenlock limestone and shale in the vicinity of 

 Dudley, is one which I feel convinced belongs to Siphonotreta 

 (de Vern.), a genus of Brachiopoda, hitherto considered peculiar 

 to the Silurian formations of Russia. The genus having been 

 ])reviously unnoticed in this country, and presenting some pecu- 

 liarities both as regards the structure of the shell and the mode 

 of attachment, it may not be uninteresting to offer a few gene- 

 ral remarks on the subject; more especially as this genus, and 

 some apparently allied forms, have been lately made the subject 

 of a special notice by Dr. Kutorga of St. Petersburg. In this 

 memoir* Dr. Kutorga has grouped together in one family (the 

 Siphon otretese) four genera, Siphonotreta, Acrotreta, Schizotreta 

 and Aulonotreta, which scarcely present any character in com- 

 mon, and have been in part considered by preceding authors 

 as belonging to different groups or distinct subfamilies of the 

 Brachiopoda. 



Differing from Dr. Kutorga upon the relative value of the cha- 

 racters of these genera, as well as their arrangement or the 

 grouping of them in one family, and certainly objecting to that 

 pernicious system of coining new generic names without a suffi- 

 ciently valid reason, merely for the sake of introducing a more 

 euphonious terminology, I cannot at the same time but freely 

 acknowledge that palseontologists are indebted to him for his 

 elaborate memoir, containing descriptions of some new and in- 

 teresting forms, illustrated with many beautiful figures of the 

 different species. 



Of the above-mentioned genera, two have been known for 

 about twenty years. One of them, remarkable for the immense 

 abundance with which it occurs in the Lower Silurian grits of the 

 north of Russia, its broken fragments disseminated in the plane 

 of stratification, giving the rock a micaceous appearance, was 

 first made known (1829) as a peculiar genus by Prof. Eichwaldf 

 under the name of Obolus {Aulonotreta, Kut.) ; about the same 

 period (1830), Pander J gave the name Ungula to this fossil, 

 which L. von Buch§ (1840) considered to be an Orthis. The other 



* 



Ueber die Siphonotreteae, von Dr. S. Kutorga, Verhandlungen der 

 Kaiserlichen Mineralogischen Gesellschaft fiir das Jahr 1847, p. 250, 

 St. Petersburg, 1848. 



t Zoologia specialis, 1829, vol. i. p. 274. 



X Beitrage zur Geognosie des Russischen Reichs, 1830. 



§ Beitrage zur Bestimmung der Gebirgsfonnationen Russlands, 1840. 



