180 



The Ottawa Naturalist [December 



MARL SHELLS FROM COBALT. 



The following species were found in a small lot of marl 

 from Cobalt, recently received from Mr. George H. Clapp, of 

 Pittsburg, Pa. Though not extensive, it is of interest, not only 

 as from that locality, but for comparison with the shells from 

 similar deposits in Michigan and elsewhere. 



I am indebted to Dr. V. Sterki for the identification of the 

 Pisidia and the notes accompanying them. 



Zonitoides arborea Say. Apparently recent. 

 Pyramidula cronkhitei anthonyi Pils. Apparently recent. 

 Physa heterostropha Say. 



Planorbis bicarinatus striaiiis Baker. The specimens are 

 not only spirally lineate, but also transversely corrugated, very 

 like the var. corrugatus Currier. 

 Planorbis campamdatus Sav. 

 Planorbis e. vacuous Say. 

 Planorbis parvus Sav. 

 Planorbis deflectus Say. 

 Planorbis hirsiiius Gld. 

 Ancylus parallelus Hald. 

 Valvata tricarinata Say. 

 SphcBrimn simile Sav. 

 Sphrerium striatinum Lam. 

 Musculium securis Prime. 

 Pisidium kirklandi Sterki. 

 with finer stria?." 



Pisidium contortum Prime. 

 Pisidium rotundaUim Prime. 

 Pisidium, noveboracense Prime. 

 Pisidium mainense Sterki . 

 regular." 



Pisidium medianium Sterki. 

 Pisidium pauper culum Sterki. 

 Pisidium tenuissimum Sterki. 

 Pisidium vesiculare Sterki. 

 seen from Canada and Minnesota, verv oblique and shape 

 different from that of the tvpes. " 



Pisidium scutellatum Sterki. "Small, juvenile." 

 "Not a specimen was seen that might be referred to P. 

 abditum. 



"It is interesting to note that most of the species are 

 represented by small, and, in some cases, specifically northern 

 forms especially that of vesiculare. Scutellatum, if mature, 

 would probablv show the same." Bryant Walker. 



'Like typical examples, but 



"Small." 

 ' ' Striae extremelv 



fine and 



'Small." 



"Small." 

 "Small". 

 "A small northern variety, 



