ANIMALS. 15] 
already noticed as occurring at Bolland, induces me to believe that it belongs to the 
Carboniferous system of this locality. According to Von Buch, it occurs at Meiningen 
and Schmerbach; and according to Geinitz, (vide ‘ Versteinerungen,’ Erklairung der 
Tab. iv) in the under Zechstein and Zechstein-dolomite of Corbusen and Konitz, 
Germany. The shell which De Verneuil has figured with the name Zerebratula elongata 
(though with a suspicion that it belongs to the present species, of which I have no 
doubt), is from the Permian marls of Itschalki, near Arzamas, in Russia. From 
some figures in Miinster’s ‘ Beitrige’ (Heft iv, pl. vi, fig. 15 a, 4), one would be tempted 
to conclude that it occurred in u.. Trias marls of St. Kassian. 
Since my remarks were printed, on “‘ the remarkable valve figured by M. de Verneuil”’ (vide ante, p. 80), 
and which I ascertained, before my Synoptical Table in page 81 was printed off, had been elevated to the 
rank of a genus, under the name of Davidsonia, by M. Bouchard Chantereaux, in a Mémoire published in 
the ‘Annales des Sciences Naturelles,’ for Aug. 1849, I have been kindly favoured by the author with a 
copy of the Memoire, in which I perceive that quite a different view is taken of the use of the “cones” from 
what is advocate. by M. de Verneuil and myself. M. Bouchard considers them as adductor muscular 
impressions ; but, notwithstanding the arguments of my learned friend, I am still in favour of their having 
been produced by the labial processes. 
From a sketch which Mr. Davidson has just sent me, of the interior of Terebratula pulchella, which 
belongs to Delthyridea, I am now satisfied that I was in error in supposing this genus to be without an 
apophysary system (vide ante, p. 141); as the species cited is furnished with a loop agreeing with that of 
Terebratula. The next question for consideration is—have Ismenia pectunculus and Rhynchora costata 
a loop? 
