276 
AUG. F. FOERSTE 
equal to the diameter of the conch, where the latter is 10 mm. 
At this point the diameter of the siphuncle* is 1 mm., and its 
distance from the dorsal side of the conch is 3.7 mm. The 
form of the siphuncle is tubular, not enlarging within the camerae. 
The conch is slightly curved lengthwise, with the dorsal side 
concave. There are about 40 vertical striae, more or less alter- 
nating in size. 
Vertically ribbed Orthoceroids of the Orthoceras laqueatum 
type occur also in the Bala beds of Great Britain, where they are 
known as Orthoceras Uneatum Hisinger. Orthoceras striatum 
Marcklin, Orthoceras suhcostatum Portlock, and Orthoceras striato- 
punctatum M’Coy are other terms whose exact value will be 
understood only after the types have been fully illustrated and 
described. 
12. Kionoceras Sp. 
Plate XXXV, fig. 2 
Orthoceras laqueatum ? var. a Hall, Pal. New York, 1, 1847, 
p. 206, pi. 56, fig. 3. 
Specimen 22 mm. long, 7 mm. wide at the base of the specimen 
and 8 mm. wide at its top, with an apical angle of about 3.5 
degrees in a lateral direction. Cross-section elliptical, the dia- 
meters at the base being 7 and 4.5 mm. respectively. There is 
no trace of septa or siphuncle; the specimen therefore may 
consist of most of a living chamber. The surface of the specimen 
is marked by 20 vertical ribs, each about a quarter of a milli- 
meter in width, the intervening grooves being three-quarters of 
a millimeter wide. The crest of the ribs is angular, and the 
elevation of the ribs is conspicuous, considering the small size 
of the specimen. The crests of the ribs are crossed by trans- 
verse striae, about 13 in a length of 5 mm., but no trace of these 
striae is noticed in the broad intermediate grooves. Possibly 
the striation is structural and within the substance of the shell 
rather than on its surface. 
Locality and Horizon. — From the lower shaly strata of the 
Trenton at Middleville, New York. The matrix of the speci- 
men contains a brachial valve of Triplecia nucleus (Hall). The 
