MOLLUSCA. 805 



elevated, with concave interspaces, and with fine longitudinal 

 lines of growth marking the surfaces ; and the whole crossed by 

 elevated thread-like raised lines, distant and distinct, but most 

 plainly marked on the ridges ; on the internal casts, the most usual 

 condition, the spire is more elevated and the form less robust, 

 with more distinct sutures and the volutions more ventricose, 

 while their surfaces are less strongly marked by the longitudinal 

 ribs, and no spiral lines are visible ; no evidence of markings can 

 be detected on the columella, either on the shell or on the cast. 

 The outer lip of the aperture appears to have been slightly thick- 

 ened, but no evidence O'f internal strise exists. The features of the 

 notch in the outer tip cannot be ascertained." (Whitfield.) 



Reinarks. — This is a well-marked and easily recognizable 

 species, and at Mullica Hill it not infrequently occurs with the 

 shell preserved. The internal casts are sometimes almost entirely 

 smooth, without any indications of the vertical folds of the shell. 



Formation and locality. — Navesink marl, Atlantic Highlands 

 (108), Middletown (113^), near Red Bank (120), near Craw- 

 fords Corner (126''), Crosswicks Creek (147*, 195), Mullica 

 Hill (169). 



Geographic distribidion. — New Jersey. 



Sub-class EUTHYNEURA. 



Order OPISTHOBRANCHIA. 



Sub-order TECTIBRANCHIATA. 

 Family AOTABONIDAB. 



Genus Actaeon Montfort. 

 Actaeon cretacea Gabb. 



Plate XCIX., Pigs. 1-6. 



1845. Tornatella Forbes, Quart. Jour. Geol. Soc. Lond., vol. i, 



p. 63, text fig. c. 

 1 861. Actceon cretacea Gabb, Proc. Acad. Nat. Sci. Phil. 



(1861), p. 318. 



