NATURAL SCIENCES OF PHILADELPHIA. 
42.3 
Length about 2*75 (100) ; width *78 (28) ; thickness *25 (9) ; projection of 
anterior extremity beyond beaks *28 (11); posterior angle formed with hinge 
line by anterior truncation 140° ; anterior angle formed by posterior trunca¬ 
tion 128°. 
Locality.— Union, Branch county, in blue argillaceous shales of the Huron 
group—the “Kidney Iron formation” of Houghton. 
But few specimens of this interesting species have been seen, and the best 
of these is defective at the posterior extremity ; and I have determined the 
total length only from a restoration founded on the incremental lines. 
The three foregoing species of Solen nearly double the number previously 
known from the Palaeozoic rocks. Messrs. Sandberger have described S. cos¬ 
tatus from the Aviculaschiefer of the Spiriferensandstein group in Nassau, 
which is supposed by them to occupy the horizon of the Marcellus Shale and 
Hamilton group. S. pelagicus, Groldf., and S. Lustheidi, d’Arch. and Vera., 
come also from the Devonian, but they are both doubtful species. The first is 
referred by d’Orbigny to Cypricardia; the latter, judging from specimens in 
Dr. Rominger’s collection from the Eifel, has the valves scarcely gaping ante¬ 
riorly, and presents much the appearance of a Solemya, (see especially So- 
lemyaprimceva, Phil. McCoy, Brit. Pal. Foss. pi. 3F.,fig. 3). Lastly, de Kon- 
inck has noticed a very imperfect solitary specimen, S . siliquoides , from the 
subearboniferous limestone of Vise, in Belgium. 
Pugiunculus, Barrande. 
Pugiunculus (?) aculeatus, Hall, (13th Rep. N. Y. Reg., p. 107).—Shell 
small, elongate, tapering, with an obtusely triangular section. Slant height 
slightly curved on all the sides and angles; sides also more convex in the 
transverse direction. The two equal sides making with each other an angle 
of 102°, and with the broader side angles of 39°. Specimen a cast without 
any external markings. 
Length *43 (100) ; breadth of sides at aperture -19 (44), *12 (28), *12 (28). 
Locality. —S. E. | S. W. | Sec. 23., Adams, Hillsdale county. 
This form lacks the evidence of striation attributed to Pugiunculus , Bar¬ 
rande ( Theca of English authors) and presents still less agreement with any 
other known genus. The original specimens were described from Rockford, 
Indiana. 
Pleurotomaria, Defrance. 
P|eurotomaria vadosa, Hall, 10th Rep. N. Y. Reg., p. 108).—Shell glo- 
bosely conical, with a width equal to its height; whorls about three, rounded 
on the exterior, somewhat flattened where they come in contact, marked along 
the middle by a moderately raised carina, on each side of which is a feeble but 
distinct revolving line, and beyond this another still feebler, and sometimes a 
third ; body whorl occupying about three-fourths of the altitude of the shell, 
regularly curved on the base, and limited by a neatly rounded umbilicus 
open to the apex of the shell. Aperture subcircular, but slightly modified by 
the body whorl; apex quite obtuse ; angle of sides 65° ; sutural angle about 
90° on the last whorl. Cast shows the revolving lines on the last whorl, but 
not on the preceding ones. 
Height of shell *44 (100) ; width *48 (109); height of body whorl *36 (82) ; 
diameter of umbilicus (in a cast) *08. 
Locality. —In a loose fragment from the western part of the State, consisting 
of an agglomerated, silicious, sintery and somewhat ferruginous mass of fos¬ 
sils, physically resembling some states of the Marshall sandstone. Described 
here in consequence of its supposed identity with a fossil from beds which 
appear to be the equivalent of the Marshall sandstone, at Rockford, Ind. 
Pleurotomaria Whitei, n. sp.—Shell with a trochoid spire, straight eolu- 
mellar lip, and prominent carinate whorls. Number of whorls three and a 
half, rapidly enlarging, raised in the middle of the dorsum in a prominent 
1862 .] 
