PRODUCTIDiE 135 



In Belgium, it is common in the limestone and shales of Tournay ; but rarer at Vise. 

 In Russia, at Cosatchi-datchi, &c. While in America it has been collected at Burlington, 

 Iowa ; Quincy, Illinois ; Hannibal, Missouri, &c. 



Orthis? antiquata, Phillips. Plate XXVIII, fig. 15. 



Terebratula antiquata, Phillips. Geol. Yorks., vol. ii, pi. xi, fig. 20, 1836. 

 Rhynchonella antiquata, Morris. 'Catalogue,' p. 146, 1854. 



Spec. Char. Somewhat elongated oval ; hinge-line straight, shorter than the greatest 

 width of the shell ; ventral valve deep and convex, but flattened towards the front ; beak 

 small, incurved ; area narrow, with an open triangular fissure (?). Dorsal valve shallow, and 

 divided into three lobes, of which the two largest diverge from the umbone to the lateral 

 margins, the third or the less produced forming a small median elevation, originating near 

 the middle, and extending to the front, where the valve assumes a somewhat triundate margin 

 and appearance. Surface smooth ; length 4, width 3, depth 2£ lines. 



Obs. Of this little shell I have seen but one example — that described and figured by 

 Professor Phillips, and which is stated to have been obtained at Bolland, and now forming 

 part of the Gilbertsonian collection in the British Museum. All endeavours to procure the 

 sight of another example have proved unavailing ; so that my observations have been con- 

 fined to the examination and description of the original type, which looks more like a small 

 Orthis than a Terebratula or Rhgnchonella, and it is therefore here at least provisionally 

 located under the genus Orthis. Professor Phillips describes his species in the following 

 words : — " a very singular, small Brachiopodous shell (perhaps Producla) of an oval figure ; 

 lower valve convex ; upper plane, with two diverging convexities ; hinge-line straight." 

 Upon such insufficient material, the species itself can only be admitted as provisional. 



Family— PRODUCTION. 



The Production have been divided into four groups, viz., Product/is, Aulosteges, 

 Slrophalosia, and Chonetes ; but they all appear to bear so natural and indeed so intimate 

 a relation towards each other, that it is very questionable whether the last three should be 

 considered more than simple sub-genera or modifications of Productus ; and this is also 

 the opinion of Professor de Koninck, to whom science is indebted for a valuable monograph, 

 of the many forms of which this family is composed. 



All the species at present known are restricted to the limits of a portion of the 

 Palaeozoic period. No British examples of Carboniferous Slrophalosia or Aalosteges have 



