1911.] NATURAL SCIENCES OF PHILADELPHIA. 585 



The above-mentioned species are evidently related to L. lirata 

 (Pfr.) =Helicina lirata and unidentata of authors, a species found on 

 the mainland from Vera Cruz to the Orinoco River; also to L. lamel- 

 losa (Guppy) of Trinidad. For this little group the name Perenna 

 Guppy might be used in a subgeneric sense. 



The typical group of Lucidella consists of the larger Jamaican 

 species: L. aureola Fer. (the type of Lucidella), L. granulosa C. B. 

 Ad. j 1850 (of which L. undulata Pfr., 1861, seems to be a synonym), 

 L. depressa Gray (the type of Paenia H. and A. Ad.), and L. adams- 

 iana Pfr. 



Lucidella yallahsensis n. sp. Fig. 2. 



The shell is nearly white, smaller than L. lineata, a little more 

 depressed, with rounded periphery. Apex smooth, the rest of the 

 shell finely and densely striate spirally; the base striate throughout. 

 Peristome expanded, thick, notched at the columella; the basal tooth 

 large and squarish, as in L. lineata; the tooth within the upper lip 

 rudimentary, represented by a slight swelling of the inner margin. 



Fig. 2. — Lucidella yallahsensis. 



Alt. 1.5, diam. 2.8 mm.; 4| whorls. 



Yallahs, parish of St. Thomas. Types No. 10211, A. N. S. P., 

 from the Robert Swift collection (probably collected by Gloyne). 



A series of over 30 individuals shows constant differences from 

 L. lineata of the Mandeville region, differences which we must look 

 upon as specific in the present state of our collections. Of this group 

 of Lucidella we now know five or six Jamaican species: 



L. yallahsensis n. sp. of the southern shore, eastward from Kingston. 



L. lineata (C. B. Ad.) of the high interior, westward. 



L. foxi Pils. and L. persculpta n. sp. of the north shore. 



L. nana Pfr. "Jamaica." 



L. trochiformis Pils. "Jamaica." 

 Geomelania. 



Of the genus Geomelania there have been described from the 

 island of Jamaica 29 species and varieties. We append an analytical 

 key to these species, which has been found useful. 



