THE NAUTILUS. 53 



the septate shell, convex on its lower surface, the margin is 

 very short, being less than half of the length of the septate 

 shell, convex on its lower surface, the margin is very concave 

 and on the right side, extends further forward than it does on 

 left, there does not seem to be the distinct thickening of the 

 margin so noticeable in other species; aperture much larger than 

 in any other species yet described. 



Length 2; width 1.5; alt. .75 mm. 



Type (43455 Coll. Walker) from the Maya Farm, Quirigua, 

 Guatemala, collected by A. A. Hinkley. Cotypes in the col- 

 lection of Mr. Hinkley. 



This fine species is the first from either Central or South 

 America, of which both the septate and adult forms are known. 



It differs from all other described species except a-epiduliaa 

 Guppy in the small size of the septum and the consequent dif- 

 ference in the position of the aperture of the septate stage in 

 the adult shell. The septum in the specimen figured appears 

 very like the incomplete septum in the North American species, 

 but as the three adult specimens before me are exactly alike in 

 the position of the septate shell, this would seem to be the 

 normal condition in this species. The specimen figured, which 

 is 3.25 mm. in length, has apparently slightly passed the sep- 

 tate stage and begun the growth of the constricted portion of 

 the adult shell and shows the beginnings of the radial striae. 



With the Gundlachias was associated a species of Lasvapex, 

 very like the ezcentriais Morelet. Whether it has any closer 

 relations with the Gundlachia remains to be determined as the 

 radula has not yet been examined. While the general aspect 

 of the two species, if such they be, is very similar, the Laevapex 

 has a very much more acute apex than the Gundlachia. 



As shown by the figure, the radula of this species is quite 

 typical of the genus. 



A LIST OF SHELLS FROM THE EAST COAST OF FLOBIDA. 



BY BRYANT WALKER. 



The late Dr. Charles A. Davis, the well known peat-expert 

 of the U. S. Bureau of Mines, in addition to his special acquire- 



