78 THE NAUTILUS. 



Gundlachia hjalmarsoni, which Dr. Pilsbry kindly identified for 

 me by comparison with some of the lot collected by Hjalmarson, was 

 first described in 1858 by Dr. Louis Pfeiffer, whose specimens came 

 from Honduras. No figure has ever been published, and the species 

 was evidently known to Crosse and Fischer and E. von Martens 

 only by the original account. One of my specimens is figured on 

 plate IV, figs. 6, 7, 8. All of the specimens found in three quarts 

 of the " drift " are of the septate form shown in the figure. I have 

 examined the material very carefully with a reading glass, and no 

 Ancylus was found. The figured specimen measures 4.1 mm. long, 

 1.8 wide, 1.2 high. 



In some Rio Grande drift from Presidio, Texas, sent to me by 

 Bryant Walker, I found a single Gundlachia, which is indistinguish- 

 able from G. hjalmarsoni, except that it is only 1^ x mm. It is 

 so small that I am sure I would not have noticed it if I had not been 

 looking for Gundlachia. It is the Brownsville shell in miniature. 



The large size, peculiar shape and strong sculpture of G. hjalmar- 

 soni distinguish it from all other species of the United States. As 

 the species is new to the United States fauna, it has been thought 

 desirable by the Editors of the NAUTILUS to append a translation 

 of the original description. 



" Shell ancyliform, oval-oblong in outline, thin, radially striatu- 

 late, pale corneous; vertex rounded, posterior; basal partition occu- 

 pying one-third the length, arcuately cut out; aperture dilated in 

 front ; basal margin not incumbent in front and behind. Length 4, 

 diam. in the middle scarcely 2, alt. 1^ mm. 



" Hab. : Santa Roza, Honduras (Hjalmarson). 



'* Just as Gundlachia ancyliformis in Cuba lives in company with 

 Ancylus, and in the same manner, so also Mr. Hjalmarson found this 

 new species in company with a weakly convex, very pale horn-colored 

 species of Ancylus, which I do not venture to name, as I have no 

 exact knowledge of the genus." (Pfeiffer, Malakozoologische Blatter, 

 v, December, 1858, p. 197.) 



The above description was made from a single example, in which 

 the septum was incomplete. Hjalmarson subsequently obtained the 

 complete septate form in the same locality. The form with a larger 

 shell added to the septate stage was not found. 



