LII BULLENIN NO 23, UNITED STATES NATIONAL MUSEUM. 



memoir if yon would send me a slight fraction or ontline sketch of the line of foot- 

 marks, -which will make the case more intelligible than ten pages of verbal descrip- 

 tion. 



Hoping to hear from yon before the 12th of September, I am, very truly, yonrs, 



WM. BUCKLAND. 



From this period Dr. Lea continued his investigatious. His papers iu 

 full may be found in the Proceedings and Journal of the Academy of 

 I^atural Sciences, and attention is called to some of the most important: 

 *' On Centemodon sulcatus " ; '' Cypricardia Leidyi,''^ the only mollusk found 

 in the Ked Sandstones near Pottsville; "Remarks on Triquetra con- 

 torta^^', "On Vision in the TJnionidw/''' -, " Observations on the Geology 

 of the New Red Sandstone near Gwynned, Pennsylvania"; "Remarks 

 on Trilobites found at Braintree, Massachusetts"; "Remarks on the 

 Existence of sl Byssus in the Unio^^-, "On the Permian of Gwynned" 

 (to which formation he was the first to assign it); "On the Greeusand 

 Formation of New Jersey"; "On both lobes of the brancljia on both 

 sides charged with embryonic shells, and red ova in several species"; 

 "On the reversed teeth of Unio"; "On the form of the Palju of South 

 American Unio^^] "On the visual and auditcry organs of the Unionidce^- ; 

 "Notes on some members of the Feldspar Family"; "On new minerals 

 from Chester County, Pennsylvania"; "Oji Microscopic Crystals in- 

 cluded iu some minerals"; " Further notes on Microscopic Crystals in 

 some of the Gems "; " Further notes on ' Inclusions' in Gems," &c. 



In addition to these there are innumerable papers during a long suc- 

 cession of years (1827-1874), on new species of the Unionidcc, Strepo- 

 onatidcB. Golimacece, &c., which were published in the Bulletin and 

 Transactions of the American Philosophical Society, and the Proceed- 

 ings and Journal of the Academy of Natural Sciences of Philadelphia. 



The number of new species, mostly from the United States, were : 



Species. 



Unio 



Anodonta 



Margaritana... 

 Syuiphynota... 



Spatha 



Pliifjiodon 



Uonocoudylcea 



Triijuotra 



li idiua 



Succinea 



Auricula 



Ovclostoma 



Pliysa 



Xyransea 



liclania 



Jo 



Mclanopsia 



Cyrena 



Aplarodite 



Holix 



CarocoUa , 



llelicina 



Acliatiua 



3'aludina 



Aiiipullaria . .. 



PolvjTyra 



Bnlimiis 



M' fiaspira 



Planorbis , 



No. 



731 

 114 



27 



11 

 4 

 1 

 9 

 1 

 1 



17 

 1 

 4 



32 



28 

 184 



10 

 2 

 4 

 1 



30 

 5 

 3 

 3 



27 

 6 

 2 



12 



Species. 



No. 



Valvata 



Anculosa 



ATunieola 



Si'hizostoina 



Basistoma 



Goniobasis ,. 



Lithasia 



Sti ephobasis 



Tri] lanostoma 



NeiitiHa 



ilycetopus 



Euryca?lon 



Maseschiza 



Mesasystropha 



Porupholyx 



Ancylus 



Rivulina 



By tliinia 



Assiminea 



Pachycbilus - 



Totol 



ro.S8il molluscii described in "Contribu- 

 tions to Geology" 



Fossil TJmonidcB described from Greensand 

 formation 



Total -.. 



1 



21 

 3 



20 



1 



175 



13 

 7 



71 

 1 

 2 

 1 

 1 

 1 

 1 

 2 

 1 

 2 

 1 

 1 



1,604 



228 



10 



1,842 



