SPIRirERID^. 



129 



distinguished by the facility with which the shell of the former cleave into, thin lamellae 

 (see p. 20 of my Chapter in your General Introduction). Large portions of it are entirely 

 destitute of perforations ; and a cursory examination might readily lead to the conclusion 

 that the shell is entirely imperforate ; but the careful examination of sections taken in 

 different directions shows that there are bands of very minute perforations opening along 

 the sides of the costse ; and although I have not been able to distinguish their orifices 

 when looking at the surface of the shell by reflected light, yet the appearances presented 

 by sections leave no doubt in my own mind that they traverse the entire thickness of the 

 shell. I do not say that these characters show that the shell is not a Retzia ; but they 

 would suggest a careful examination of its other characters ; since, as the very interesting 

 case you give of the so-termed Fentamerus carbonarius of M'Coy additionally shows, all 

 the supposed anomalies in regard to punctation disappear before a thorough investigation 

 of internal structure." — (London, 22nd November, 1866).^ 



Position and Locality. Betzia Barrandii occurs abundantly in some few localities, 

 such as in the Wenlock Limestone or Shale at Hay Head, near Walsall, near Dudley ; 

 and at Buildwas near Wenlock ; also at the base of the Wenlock Shale in Malvern 

 Tunnel; and in the Woolhope Limestone of the same locality (J. W. S.). 



It is also found in the Island of Gothland by Dr. Lindstrom. 



Genus — Atrypa, Bahian, 1827 (Spirigerina, jy Orhigny). 



Bef. — Davidson, ' General Introduction/ p. 90. (Type, Atrypa reticularis, Linn.) 

 The characters belonging to this genus have been so often described by myself and 

 other palaeontologists that it will not be necessary to refer to them again in this Monograph. 



Atrypa reticularis, Liniie (sp.). PI. XIV, figs. I to 22. 



Anomia reticularis, LinnL Syst. Nat., ed. xii, p. 1152, 1767. 



Terebratula pectinata, Bruguiire. Hist. Nat. Vers. Test. ; Encyl. Meth., pi. 242, 

 fig. 4, 1789. 



Tekebratulites asper, ScMoth. Leonhard's Tasehenbuch, p. 74, pi. i, fig. 7, 1813. 



— PRiscTJS, Id. Petref., p. 2G2 ; Nachtr., pi. xvii, fig. 2 ; pi. -xx, 



fig. 4, 1820. 



— EXPLANATUs, Jc?. Nachtr., pi. xviii, fig. 2, 1820. 



Anomites reticularis, Wahlenberg. Nov. Act. Soc. Upsal., vol. viii, p. 65, 1821. 



1 Prof. Hall, to whom I had sent specimens of our R. (?) Barrandii, informs me that he believes it to 

 be referable to his genus Coslospira (Hall, 1863, 'Sixteenth Report on the State Cabinet,' p. 60; Type, 

 C. concava=Leptocoelia concava ; Family, Syiriferidm ?) ; but that he has some doubt whether he should 

 now make Zygospira (Hall, 1862, generic descrip., 'Fifteenth Report on the State Cabinet,' p. 154 ; Type, 

 Z. modesta, Say, sp. ; Family, Spiriferida) distinct, they being all small shells, and difiicult to manipulate. 



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