432 Mr. 1\. Etlieridj^e on Varboaiferoiis LaineUib ranch iata. 



having Ix'cu gregarious ; but the specimens from Fife were in 

 better preservation, and he intended to have them hiid open 

 and submit them to a careful examination in order to deter- 

 mine the generic characters. Circumstances jn'cvented this, 

 but it \vAs now l^een made clear by Mr. Salter." ^lany years 

 ago Dr. Rhind figured, but did not describe, under the name 

 oi' Aximis Pent/dnih'ctus*, two shells from Woodhall (probably 

 the Colinton of the above quotation), which I believe to be 

 specitically distinct from one another. One of thesef was after- 

 wards refigured and described by Capt. T. Brown as Pachyudon 

 jyyramidatusXj witiiout any reference to Rhind's figure, and 

 again as Uiiio pyramidal ua^. 1 am at present under the im- 

 pression that Rhind's tig. h and Brown's P. [Unio) pyramidahis 

 are the same shell as the present species, which 1 have ven- 

 tured to describe under the name of S. Salteri, in memory of 

 an early preceptor and friend to whom I am indebted for many 

 pleasant rambles and much profitable instruction. The pos- 

 terior slope of JS. Salteri is very frequently broken or crushed 

 away, when the individuals bear a close resemblance indeed 

 to the above shells, in which there is no slope figured, the 

 ])Osterior side consisting of a blunt acumination. If future 

 investigation should prove them to be identical, Capt. Brown's 

 s[)ccitic name will have to be adopted. The Rev. Thomas 

 Browni has most obligingly allowed me to examine the original 

 specimens in his cabinet used by Mr. Salter for the woodcuts 

 cited above. Of these, fig. 1 represents the internal umbonal 

 region of the right valve, and shows the anterior tooth of the 

 natural size. In fig. 2 we have a view of the whole of the 

 interior of the left valve, with an enlarged drawing of a 

 portion of the hinge, and showing the plain suriace and wedge- 

 form of the tooth, which in some Schizodontes is bifid. The third 

 figui'e is a good external representation of the left valve, with 

 the general characters well indicated, except that the lamina? 

 of growth on the upper half of the shell are too pronounced. 

 It is an enlarged figm-e, although the species frequently 

 reaches the size indicated. In the thick undivided nature of 

 the central tooth of the left valve, ;S'. Salteri quite agrees witli 

 two other Carboniferous species in which the dental arrange- 

 ment has been noticed — *S'. carboaarius, Sow., and S. a-riui- 

 formisj Phil. ; in both of these the corresponding tooth is 

 simple and thick II, thus presenting a marked difference from 



• Age of the Earth, t. 2. f. u tc h. 



t Fi^'. h. 



X Annals Nat. Hist. 1848, xii. p. ;j<J(i. t. Hi*, f. t>. 



§ Fossil Concholojry, ^. 17!». t. T:}. f. I'J. 



I King, Mon. Tcnu. tosy. p. 1^7. 



