R. ETHERIDGE, JTN., 02s A LOWER-CARBONIFEROUS PRODCCTUS. 455 



through which, he considered, passed small tendons of attach- 

 ment *. 



1831. M. G. P. Deshayes, in giving the characters which separate 

 the genera Terebratula and Productus, drew attention to the absence 

 of any foramen in the beak of the latter, the resulting want of a 

 peduncle, and probable free condition of the shell f . 



1832. The same author, in his continuation of Bruguiere's ' En- 

 cyclopedic Methodique,' stated that Productus showed no trace of 

 attachment, and lived a free life after the manner of a large number 

 of the Acephalous Mollusca J. 



1835. The Eev. A. Sedgwick and Sir It. I. (then Mr.) Murchison, 

 in their paper " On the Geological Eelations of the Secondary Strata 

 in the Island of Arran "§, describe Producta scotica, Sow. (=P. 

 semireticulatus, Mart.) as occurring in the Carboniferous Limestone 

 of the Corry Caverns so abundantly " as entirely to form the lower 

 layer of many of the beds, being arranged very symmetrically in the 

 exact position of the living shell [misprinted shale] with their con- 

 vex valves downwards." 



1836. M. G. P. Deshayes, in the second edition of Lamarck's 

 famous work ||, states that from the absence of spines in some Pro- 

 ducti he was disposed to abandon his opinion regarding the use of 

 the tubes or spines as a passage for tendinous appendages (appendices 

 tendineux) of attachment, replacing the peduncle of Terebratula %. 



1838. M. von Buch, in his ' Essai d'une Classification et d'une 

 Description des Terebratules '**, divides the Brachiopoda into two 

 groups. In the non-perforate division of the second section of the 

 first group, or those with the point of attachment from the edge of 

 the upper valve below the hinge-margin, M. von Buch placed the 

 genera Calceola and Leptama, including in the latter Productus and 

 Stropliomena. 



The views previously enunciated by M. von Buch as to the nature 

 of the tubes in Productus, appear to have been abandoned by that 

 eminent naturalist in his memoir " Ueber Productus 0(lerLej)tama ,, tt. 

 He there considers it very doubtful if the tubes or spines were used 

 for fastening the shell ; for he found that in some species, instead of 

 being confined to the hinge-line, they were scattered over the shell, 

 as in Productus aculeatus. 



* Abh. d. k. Akad. Wiss. z. Berlin, aus dem Jahre 1828 (pub. 1831), pp. 53-56. 



t Descr. des Coq. caraeteristiques des Terr. p. 112. 



| Encyclopedie Methodique : Hist. Nat. des Vers, par Bruguiere et de La- 

 marck, continuee par M. Gr. P. Deshayes, iii. p. 846. 



§ Trans. Geol. Soc. 2nd ser. iii. p. 30. 



|| Hist. Nat. des Anim. sans Verteb., par J. B. P. A. de Lamarck. Deuxieme 

 edition, par MM. G-. P. Deshayes et Milne-Edwards, vii. pp. 378, 379. 



^[ According to Prof, de Koninck, the division by M. Deshayes of the Tere- 

 bratuliform shells into two genera, Terebratula and Productus, on the presence 

 or absence of any opening in the beak, was an erroneous one. Deshayes placed 

 in Productus all those with an articulated hinge in which the opening is quite 

 obliterated, and completely neglected the presence and form of the area &c. 

 (Anim. Foss. Terr. Carb. Belg. p. 150, and Mon. Productus et Chonetes, p. 8). 



** Mem. Soc. Geol. de France, iii. p. 126. 



tt Abh. d. k. Akad. Wiss. z. Berlin, aus dem Jahre 1841 (pub. 1843), pp. 53-56, 



