102 THE NAUTILUS. 



anterior slope is nearly straight; the posterior slope slightly 

 concave; the left lateral slope nearly straight or only slightly 

 convex and the right lateral slope concave; the apex is ohtuse, 

 smooth except for concentric wrinkles, situated nearly on the 

 nedian line, slightly turned toward the right and at about one- 

 third of the length; the lines of growth are tine, but distinct 

 and regular, the surface is somewhat obsoletely wrinkled to- 

 wards the margins, but there are no indications of radial striae; 

 the color is a yellowish horn-color, slightly tinged with green. 



Compared with F. diaphana < Hald. ) and F. kirklandi (Walk. ) 

 to which it is most nearly related, it is less circular in outline, 

 the apex is more prominent, the lateral and posterior slopes are 

 unlike and the color is different from the former, and it is less 

 elongated and has the apex more obtuse and less excentric than 

 the latter. 



So far as appears from the small series examined, it would 

 seem to be clearly entitled to specific distinction. 



III. 



FERRISSIA (L.^VAPEX) DALLI, n. sp. 



? Ancyliis obscurus Clessin, Con. Cab., Ancylus, 1882, p. 19, 

 pi. VI. fig. 4. 



Ancycus obscurus? Walker, NAUT., XIII, 1903, p. 26, pi. I, 

 figs. 16-18. 



Type locality, Lake Helena, Volusia Co. , Fla. 



Type No. 25521 Coll. Walker. Cotypes in the collection of 

 A. A. Hinkley. 



Tne doubt expressed in my paper of 1903 (1. c. ) as to the 

 identity of the Floridan species referred to obscurus Hald. by 

 Ball proves to have been well taken. As shown by a compari- 

 son qf the description and figures given in 1903 as cited above 

 and those of the genuine obscurus herein, the Floridan species 

 is entirely different and is more closely related to F. peninsulas. 

 (P. and J. ) than it is to obscurus. 



I have already (1. c. ) called attention to the resemblance of 

 the shell described and figured by Clessin as A. obscurus to this 

 form. He gives no information as to the history of the speci- 



