INSTITUTE OF SCIENCE, PHILADELPHIA. 407 



adult imperforate. So it is evident too much stress must not be laid on this 

 single character. 



The group extends through the whole of the Tertiary, beginning in the 

 Mesozoic, and is abundantly represented in the present fauna. 



In the Eocene the following species occur : 5. elegans Lea, with which 

 stalagmuuit Conrad (which was named first, but not recognizably defined or 

 figured before Lea's publication) and S. periniini De Gregorio are synonymous. 

 According to Meyer, Delphinula solarioides Heilprin is also identical with 

 elegans, but I have not examined the type. A variety modesta, in which the 

 spiral sculpture is obsolete, has been described by Meyer and Aldrich. This 

 species occurs at Claiborne, and also at Wood's Bluff, Ala., the variety at 

 Wahtubbee, Miss. 



Solariella cancellata Lea and Conrad is extremely similar to some of the 

 recent deep-sea species of the Antillean region. It is known from the 

 Claiborne sands. Wood's Bluff, White's marl-bed in Monroe Co., Ala., and at 

 Dry Creek, Jackson, Miss. 



Solariella lineata Lea (as Turbo), from the Claibornian, has no crenula- 

 tions around the umbilicus, the margin not being carinate,but rounded ; it is 

 obviously a member of this group, nevertheless. Troclms alabamiensis Aldrich 

 much resembles a Margarita, but has the profuse sculpture and crenulated 

 umbilical keel of Solariella. It comes from Prairie Creek and Matthews' 

 Landing, Ala. It is probable that the Solarium semidecussatiim of Guppy, 

 from the Older Miocene of Haiti, is a Solariella, though neither figure nor 

 description is distinctive enough for recognition. 



Solariella louisiana n. .s. 

 Plate 23, figure i. 



Eocene of McKay's marl-bed, near Enterprise, Miss., and at Lisbon ; in 

 Alabama at Lower Peach Tree Creek, a branch of the Alabama River, 

 Hatchetigbee Bluff, the lower bed at Wood's Bluff, and Butler, Choctaw Co. 



Shell small, subconical, with five or six whorls; nucleus small; whorls 

 rounded, with a flattened space in front of the suture, which is distinct and some- 

 times even slightly channelled; the flattened area is bounded anteriorly by an 

 elevated spiral thread, which, especially on the earlier whorls, is more or less 

 distinctly beaded; beside this the surface is sculptured with spiral grooves 

 separated by about equal interspaces and crossed obliquely by numerous 

 impressed lines, rather evenly spaced and in harmony with the lines of growth ; 

 the sculpture throughout is stronger on the upper part of the whorls and on 

 the earlier whorls, on the last whorl it is more or less obsolete in nearly all 

 the specimens; the periphery is evenly rounded ; the base slightly flattened ; 

 the umbilicus large and funicular, its walls sculptured in both directions, the 

 spirals distinctly beaded; the umbilical carina is crenate, with a narrow sulcus 

 formed by two or three impressed lines, outside of the carina ; aperture very 



