Remarks upon the Genus Anomalodonta, etc. 329 



fie difference, as he, probably, has never had the pleasure of seeing 

 either species, I will add, that there are no imbricating lines of growth 

 on the gigantea, except near the margin, and that they lie flat upon 

 the shell and are not visible on the interior part of the shell, and are 

 not, therefore, preserved on casts of the interior. While the imbrica- 

 ting lines on the alata are placed at regular intervals across 

 the shell, as shown by Prof Meek's figure. They do not always 

 lie flat, but frequently curve up, so as to allow a knife blade to 

 be introduced between the two parts of the shell, and when viewed on 

 the interior, one part of the shell appears as if laid upon the other, 

 like clapboard shingles on a log school-house, and the depression inci- 

 dent thereto produces a corresponding elevation on the casts. This 

 difference alone is sufiicient to characterize the species. 



But, the Professor says, that "Mr. Miller seems to have relied 

 solely upon the large size and the preservation of concentric strise of 

 his shell to separate it from M. alata" I do not know where the Pro- 

 fessor acquired this information, for I certainly never entertained or 

 expressed any such views, or wrote anything to warrant any such 

 inference. The declaration is, therefore, not onl}^ untrue, but wholly 

 gratuitous. The only comparison made with the A. alata, consisted 

 in the bare statement, that it was readily distinguished by the surface 

 markings. And so it is, as shown by the descriptions, and by the en- 

 gravings, and the fact is plain to every one who has seen the speci- 

 mens ; and, lest the Professor should be of the same opinion still, it 

 may be proper to state that the concentric strise referred to are com- 

 mon to the Anomalodonta gigantea, A. alata, Amhonychia racliata, and 

 other species belonging to these genera. 



As it must be quite evident to every one, that the specific difter- 

 ences between the alata and gigantea are obvious, from an exterior or 

 interior view of the shells, and may be detected in the casts, we will 

 pass on to the other points made by the Professor, where the blunders, 

 if not so apparent, are yet quite as bold. 



In the July number of this Journal, page 211, some doubt is ex- 

 pressed about classifying such equivalve shells as the Anomalodonta 

 and Ambonycliia in the inequi valve family Aviculidce and a compari- 

 son is drawn between the hinge lines of the Anomalodonta and Myalina. 

 One can hardly help thinking that the Professor has read this, though 

 he don't say so. 



The learned paleontologist, Prof McCoy, placed the genus Amhony- 

 chia in the fixmily Aviculidce, but only casts w'ere then known, and he 

 supposed it to be an ine(|uivalve shell, and lesser Professors since his 

 time have continued the same classification, without apparent exam- 



