2j6 NEW YORK STATE MUSEUM 



species with which we are not otherwise acquainted. It measures in length 

 28 mm and in night 23 mm. 



Habitat. Genesee province ; Chautauqua subprovince. Forestville. 



Loxopteria (Sluzka) intumescentis sp. now 



Plate 14, fig. 8-17 



Shells subcircular or irregularly subrhomboidal in outline, broader over 

 the body, sometimes the greater diameter transverse, sometimes vertical. 

 The prodissoconch is very prominent with the apex directed strongly for- 

 ward. Its position is subcentral, but, on account of the varying outline 

 of the shells, lies now in front and now behind the middle. A vertical line 

 dropped from beak to base divides the shell into unequal parts, of which 

 the larger is the anterior. Behind the beak the margin is straight for a 

 very short distance (hinge), then bends more or less abruptly downward to 

 a broadly rounded ventrolateral curve. The base may be transverse or 

 curved and the anterior margin is a shorter curve than the posterior. The 

 anterior moiety of the shell is more extended and narrower than the pos- 

 terior. Surface pretty evenly convex with a narrow abrupt slope on the 

 postcardinal margin. Surface markings irregular concentric growth lines 

 and wrinkles. 



Habitat. Genesee province; Chautauqua subprovince. From Wal- 

 nut creek at Forestville and Correll's point, Lake Erie. 



Observations. This description is derived from shells which seem to 

 be all left valves. There is no wide departure in their general aspect from 

 that of Loxopteria dispar and L. laevis, but, in the absence of 

 the triangular form, broader posterior expansion, narrow anterior moiety 

 and almost direct anterior margin, are found differentials which seem to 

 justify a separation of the species in a subgeneric way from Loxopteria. 

 The same differences are present in L. corrugata, which belongs in this 

 association rather than with the typical representatives of that genus. We 

 have therefore proposed to designate these two species by the subgeneric 

 term above used. 



Such shells as these are to be found among the various species referred 



