THE NAUTILUS. 59 



2. Grabau, A. W. Guide to the Geology and Paleontology of 

 Niagara Falls and Vicinity. Bull. Buff. Soc. Nat. Hist., vii, 1901, 



No. 1. 



3. Fowke, Gerard. Pre-glacial Drainage Conditions in the 

 Vicinity of Cincinnati, Ohio. O. State Acad. Sci., Special Papers* 

 No. 3, 1900, p. 68. 



4. Taylor, F. B. A Short History of the Great Lakes. Studies 

 in Indiana Geography, x, 1897. 



5. Walker, Bryant. The Distribution of the Unionidas in Michi- 

 gan, 1898. 



MAEINE SHELLS FROM DRIFT ON TIPPER MATECUMBZ KEY, FLORIDA. 



BY JOHN B. HENDERSON. 



In May last while cruising down the Florida keys in the " Eolis," 

 Mr. Simpson, Mr. Clapp and I went ashore on Upper Matecumbe 

 for an assault upon the land shells. Returning along the beach we 

 observed a little sheltered cove, wherein the usual line of small drift 

 shells appeared to be exceptionally rich. We scooped up a pill-box 

 full containing about the measure of an ordinary tablespoon of this 

 rubbish. The appended list of species therein contained may be of 

 interest. The presence of Pyrazus milium Dall is noteworthy, as 

 this little Cerithium has only recently been described from the Pleis- 

 tocene of Panama. The Sayella crosseana Dall is also interesting. 

 This specimen is perfect, of a rich chestnut-brown, and greatly re- 

 sembles a miniature Obeliscus from Cuba. There are some other 

 species in the lot, but the shells are too young or worn for positive 

 identification. 



Rissoina chesnelli Mich. Crepidula fornicata L. (young). 



Rissoina laevigata C. B. Ad. Acmaea punctulata pulcherrima 



Rissoina decussata Montagu. Guild. 



Rissoina cancellata Philippi. Siphonaria alternata Say 



Alvania lipeus Dall. (young). 



Litiopa bombyx Kiener. Phasianella pulchella Orb. 



Caecum floridanum Stimp. Neritina viridis Lam. 



Caecum cooperi Smith. Neritina virginea L. (young). 



Meioceras nitidum Stimp. Ischnochiton papillosus Ad. 



Seila terebralis C. B. Ad. Eulima gracilis C. B. Ad. 



Cerithium variabilis Ad. (small Pedipes mirabilis Muhlf. 



race). Actaeon punctostriatus C. B. 



Pyrazus milium Dall. Ad. 



Triforis nigrocinctus C. B. Ad. Tornatina canaliculata Say. 

 Bittium varium Pfr. Tornatina candei Orb. 



Mangilia biconica C. B. Ad. Truncatella bilabiata Pfr. 



