THE NAUTILUS. 141 



Pupa hordeacea Gabb. 



There has also been nuich uncertainty about tliis form, since under 

 its name no less than 3, and possibly more, difi'erent ones have been 

 sent out by the author himself, and the descriptions published of it 

 did not agree at all.' Yet it has been decided to let the name stand 

 for a species related to procera, but having the shell larger (averag- 

 ing alt. o'U diam., l"o millim.), the aperture of a difi'erent, some- 

 what rhombic shape ; the crest behind the palatal margin is more 

 or less white, corresponding to a rather strong callus ; the palatal 

 wall just behind the crest is considerably flattened, and the base 

 rather compressed, keel-like. 



P. Iwrdeacea is decidedly variable ; among the typical form there 

 are numerous albino specimens ; some show hardly a trace of a lam- 

 ella on the palatal wall ; from certain parts of its range, there are 

 examples more conical and somewhat lighter colored, approaching 

 P. seri'/7ts Gould. The species is found in Texas, New Mexico and 

 Arizona. As already mentionetl, it comes very near P. procera on 

 one side, and shows much resemblance to servilis on the other, 

 while it has a well characterized " strain" of its own. But with these 

 interrelations, it is all the more interesting to the naturalist who de- 

 sires something else than simply filing so and so many " well defined" 

 species only. 



Pupa hordeacella Pihbry. 



Tliere is hardly a controversy about the synonymy of the species. 

 It is characterized by its size, averaging the smallest of the group 

 on the continent, the thin shell, its distinct striation, the flattened 

 last half of the body whorl, the base being comparatively broader 

 and more rounded than in its congeners and by the thin apertural 

 margins. But it is also variable to a considerable degree ; as to 

 size, the smallest I have seen measuring 1'4, the largest 2*4 millim. ; 

 as to color, from pale horn to light chestnut ; and pure albinoes are 

 quite common in some places. The smallest specimens generally 

 have a remarkably lesser number of whorls comparatively. 



Its area of distribution, as far as known, is from Florida through 

 Mississippi and Texas to New Mexico and Arizona. 



1 Since the original description (Am. Journ. Conch. II, Ocl., 1866, p. 331) 

 was inaccessible to me, Mr. Dall had the very estimable kindness to forward me 

 a copy of it and of the figure ; from both it would be absolutely impossible to iden- 

 tify the species. — Conf. also W. G. Binney, Bulletin 28, p. 173. 



