GASTEROPODA OF THE LOWER GREEN MARLS. 119 
Genus ALARIA Morris. 
ALARIA ROSTRATA. 
Plate xiv, Figs. 5-6. 
Rostellaria rostrata Gabb: Jour. Acad. Nat. Sci., Phila., 2d ser., vol. 4, p. 390. 
Pl. uxvint, Fig. 7. | 
Gladius rostrata Gabb: Synopsis, pp. 58, 77. 
Anchura rostrata (Gabb) Meek: Geol. N. J., Newark, 1868, p. 729. 
Anchura (Drepanochilus) rostrata (Gabb) Meek, Check List Cret. and Jur. Foss., 
p. 19. 
Shell of only moderate size; spire elevated, forming an apical angle of 
about 35°, but somewhat variable in different specimens; whorls about six 
in number, very slightly convex between the sutures, which are not verv 
strongly marked, and are ornamented by rather closely arranged vertical 
folds, smaller, more numerous, and more closely arranged on the upper than 
on the body whorl; those on the last whorl become smaller, shorter, and 
more indistinet toward the expanded lip, on the back of which they become 
obsolete; on all the upper whorls the folds extend from suture to suture, 
but on the last one they are marked only on the upper or larger parts; outer 
lip expanded, forming a broad, wing-like extension which is prolonged below 
along the moderately long rostral beak, and above is extended mto an 
obtusely pointed hook-like process from its outer upper border. ‘This fea- 
ture I have seen entire ouly on the type specimen, though several are betore 
me which show the expansion of the lip. No keel-like ridge marks the 
back of the lip, as in most of the species of this group from the Cretaceous 
beds of the Upper Missouri region. | 
This species may be distinguished from the others of the group from 
New Jersey by its smaller size, smaller and more closely arranged vertical 
folds, and proportionally shorter and more obtuse spire. There appears to 
be a very great degree of variation among the specimens of this species in 
the proportions of the spire, some of them being very much more slender 
than the rate of increase mentioned above. There is also considerable 
difference in the strength and number of the vertical folds, but none of them 
approach in coarseness that of the most nearly allied forms associated with 
it in New Jersey, from which this feature alone will readily distinguish it. 
Formation and locality: In the brown layers of the Lower Marls near 
Burlington, New Jersey, where it appears to be a somewhat common species. 
