1854.] 



HAMILTON MAYENCE BASIN, 



281 



With regard to the proper parallelism of this formation, I may 

 quote the words of Dr. F. Sandberger, who, after giving the various 

 localities in which each of these fossils is found, observes that " out 

 of the whole list of twenty-eight species common to the Cyrena- 

 marls and other tertiary deposits, eighteen are common to the Middle 

 Limburg formation, and eight to the upper marine sand of Paris ; 

 but, as we have found a still larger number of species which these 

 formations have in common with the sands of Weinheim, and have 

 consequently recognized them as the equivalent of the Middle beds of 

 Limburg, and as the Cyrena-clay is proved by its position to be newer 

 than the sands of Weinheim, I believe that it must be paralleled with 

 the Upper Limburg and the Septaria-clay of Northern Germany." 



I have already observed that the "freshwater limestone" of the 

 German geologists must be considered as the lowest member of the 

 Cerithium-limestone, we must therefore take the two following lists 

 together ; No. III. being that of the so-called "freshwater limestone," 

 and No. IV. that of the Cerithium-limestone. 



Table III. 



Fossils of the "Freshwater Limestone of the Germans" (No. 3 of 

 the list at p. 260.) 



Littorinella acuta, Besh. 



Neritina picta, Fer. 



Cerithium subcorrugatum, d'Orb. 



submargaritaceum, A. Brawn. 



Planorbis parvulus, Reuss. 

 Limnaeus Thomaei, Reuss. 

 Auricula minutissima, A. Braun. 

 Truncatella microceras, A. Braun. 

 Acicula subtilissima, A. Braun. 



suturalis, A. Braun. 



Cyclostoma (Craspedopoma) utriculo- 



sum, Sandb. 



(Megalomastoma) Dolium, Thorn. 



(Cyclostomus) bisulcatum, von 



Zieten. 



(Pomatias) labellum, Thorn. 



Vitrina intermedia, Reuss. 

 Helix Kamondi, Brongn. 



Brauniorum, Thorn. 



deflexa, A. Braun. 



var. a., communis, 



/3. hortulana, Thorn. 



y. minor, 



oxystoma, Thorn. 



subsulcosa. Thorn. 



similis, Thorn. 



Kalmitana, A. Braun. 



Rahtii, A. Braun, Th. 



phacodes. Thorn. 



lapicidella, A. Braun. 



pulchella, Mull. 



var. y. costellata, A. Braun. 



uniplicata, A. Braun. 



lepidotricha, A. Braun. 



Helix osculum, Thorn. 



var. a. communis, 



affinis. Thorn. 



■ involuta, Thorn. 



var. a,, communis, 



pupula, A. Braun. 



var. a. Corculum, A. Braun. 



/3. paludinseformis, A. Braun. 



stenotrypta, A. Braun. 



Helix verticilloides, A. Braun, Th. 



var. /3. euryomphalos, A. Braun. 



hypoleios, A. Braun. 



/3. compressa, A. Braun. 



— — discus. Thorn. 



disculus, A. Braun. 



nana, A. Braun. 



subcellaria, Thorn. 



sublucida, A. Braun. 



nitidulosa, A. Braun. 



Bulimus gracilis. Thorn. 



Achatina (Glandina) subsulcosa. Thorn. 



( ) Sandbergeri, Thorn. 



( ) lubricella, A. Braun. 



Clausilia exarata, Ziegl. 



Pupa variabilis, Drap. 



var. ji. gracilis, Sandb. 



cylindrella, A. Braun. 



Dolium antiquum, A. Braun. 



quadrigranata, A. Braun. 



subdentata, A. Braun. 



cryptodonta, A. Braun. 



var. |8. la^vis, A. Braun. 



(Vertigo) trifurcata, A. 



( ), n- sp. 



X 2 



