394 THE CHICAGO ACADEMY OF SCIENCES. 



"Upper Mississippi drainage; south to the Cumberland 

 and Arkansas rivers; Red River of the North." 



"This species has generally been confounded with its near 

 ally, Lampsilis anodontoides Lea. It is a smaller, more inflated, 

 and in every way a more delicate form than the latter, is not so 

 high, the epidermis is brighter and more glossy, and generally 

 rayed. The postbasal inflation of the female is usually more 

 pronounced, and the posterior point is higher than in anodon- 

 toides. The latter is usually more yellow or tawny than falla- 

 ciosus, and is, on the whole, a heavier shell." 



"In L. fallaciosus there is a horny, brown, raised streak on 

 the inside of the mantle behind, that I do not find in auodon- 

 toides, and the palpi of the former are shorter." (Simpson.) 

 It is confined to the western region, and has been collected 

 only in Hickory Creek, near Joliet. 



p. 1 06. Lampsilis spatulatus Lea should be called Lampsilis 

 ellipsiformis Conrad (Unto ellipsiformis CONRAD, Monograph, 

 Vol. VIII, p. 60, pi. xxxiv, fig. i, 1836). 



p. log. Lampsilis parvus Barnes. This species has been 

 found in the Little Calumet River and is abundant in a creek 

 near Blue Island. Mr. Jensen has given the following measure- 

 ments of a specimen in his collection: length, 41.00; height, 24; 

 breadth, 19.50 mill. 



p. 113. Species No. 37 should be changed as follows: 

 37. Sphserium vermontanum Prime, pi. xxvii, fig. 4. 



Spharium vermontamtm PRIME, Proc. Phil. Acad., p. 128, 1861. 



Shell: The description on pages 113 and 114 holds good. 

 The following additional measurements have been made: 



Length, 12.00; height, 10.00; breadth, 7.00 mill. (Lyon coll.) 

 11.50; " 9.00; " 6.50 " " " 



11.50; " 9.00; " 7.50 " " " 



13.50; " 10.50; " 8.00 " " " 



Animal: Not observed. 



Distribution: Lakes Champlain and Memphremagog, Ver- 

 mont (Prime); Shoreham, Vt., and Holland, Mich. (E. W. Roper, 

 in letter); Michigan (Bryant Walker, after DeCamp); Lake 

 Michigan, at Miller's, Ind., and Chicago, 111. (Dr. H. N. Lyon); 

 Hickory Creek (J. H. Ferriss). 



Geological distribution: Pleistocene. 

 Habitat: Found generally in the larger lakes. 

 Remarks: This species was at first identified as solidulum 

 Prime, but specimens submitted to Mr. E. W. Roper, a short 



