129 



and encircled with from one to four revolving keels in addition to the 

 spiral ribs. 



Sucia Islands, in Division A.; J. Richardson, 1814. Fourteen good 

 specimens. Five of these belong to the typical form of the species 

 and five to the variety carinifera, but the remainder, all of which are 

 very small shells, form a connecting link between the two extremes, 

 being wider than high as in the keeled variety, but resembling 

 the type in the want of a prominent iingle below the middle of the 

 body whorl and in not being encircled by any revolving carinfe. 

 The typical form grows to a considerable size ; the largest individual 

 (the original of figure 4, on plate 16), when perfect, was probably two 

 inches and a half in length, but the largest example of the keeled 

 variety yet obtained is not more than eight lines long. The large 

 specimens, also, have had their original shape much altered by pressure. 



It would seem that this is the only true Stomatia at present known 

 from rocks of Cretaceous age. Stomatia gaultina of Pictet and Eoux 

 has been removed from that genus by Pictet & Campiche, and placed in 

 Iveritopsis, while the Stomatia aspera of D'Orbigny (Pal. Franc, Terr. 

 Cret., Vol. 11., p. 237, pi. 188, tig. 4-7) is almost certainly a Catinus. 



AnISOMYON MeEKII, GaBB ? VAR. 

 Anuomyon Meekii, Gabb.— Pal. Cal., Vol. l,p. 142, pi. 21, fig. 105. 



Shell conical, moderately elevated, sides sloping obliquely in all direc- 

 tions, neither concave in front nor convex behind ; base ovately-oi'bicular, 

 a little longer than wide ; apex acute, nearly erect but with a verj^ slight 

 inclination towards the posterior end, and situated a little in advance of 

 the middle. Surface apparently marked with crowded concentric stria- 

 tions ; muscular scars not visible. 



Lower Shales, Division B, of the banks of the Trent River, V. L, above 

 the falls; J. Richardson, 1871. To^o large but imperfect and badl}- pre- 

 served casts, also a small but more perfect specimbn with the test partly 

 exfoliated. 



On the posterior slope of the smaller of the two casts, a mesial carina 

 runs from the apex to the base, as in the Anisomyon borealis of Meek and 

 Hayden,* but no such keel is perceptible in the other two specimens. In 

 the typical A. Meekii, from the Shasta Group of Californir., the a])ex 



• See Meek'sEeport on the Invertebrate Cretaceous and Tertiary Fossils of the Upper Mis- 

 souri Country, p. '^88, pi. 18, flg. 9. 



