1919.] NATURAL SCIENCES OF PHILADELPHIA. 223 



Livingston, Guatemala, collected by A. A. Hinkley. Type and 

 cotypes, No. 45178 A. N. S. P. 



This species was collected in considerable quantity by Mr. Hink- 

 ley; but although locally common, and belonging to a group in which 

 species usually have a wide distribution, I have been unable to 

 trace this shell in the literature. It is certainly distinct from D. 

 striata, the common Donax of the Mosquito Coast. It resembles 

 Roemer's figures of his D. siliqua, from an unknown locality, but 

 in that species the beaks are more posterior (at the posterior fourth) , 

 and the posterior carina is therefore steeper; the posterior area is 

 somewhat granulose and its outline more convex. Moreover, the 

 teeth differ. None of the new forms in Bertin's monograph (Nouv. 

 Arch, du Mus.) is nearly related. 



Note. — Since this article was in type I have found that Schepman, 

 in his Prosobranchia of the Siboga Expedition, Part I, 1908, p. 13, 

 has already noticed the peculiarities of Neritilia, and figured the 

 teeth of N . riihida, from Celebes. It is interesting to find American 

 species with a similar radula. 



Explanation of Plate XL 



Fig. 1. — Spiraxis guatemalensis n. sp. 



Fig. 2. — Spiraxis longior, n. sp. 



Fig. 3. — Pseudosuhulina martensiana n. sp. 



Fig. 4.- — Succinea panamensis n. sp. 



Figs. 5, 5a.— Pseudohyalina viaya n. sp. 



Fig. 6. — Guppy a Jalisco, n. sp. 



Figs. 7, 7a. — Pseudohyalina opal, n. sp. 



Fig. 8.- — Physa solidissima n. sp. 



Fig. 9.—Cyrenoidea guatevwlensis n. sp. 



Fig. 10. — Donax mediamericana n. sp. 



10 



