40 D1IVM 1 I >. MI.XICO AND CENTRAL AMERICA. 



microscopic, close spiral stria- more clearly on the base. The main 

 distinction, however, is geographic, serperastrum being an eastern, 

 -.li'i/Ii'ri a western form. So 1'ar as present information L:<>es, its 

 range is separated from that of serjiertistrnm by tlie table-land of 

 Mexico. 



The original description of B. zi<'</l<'ri 1'fr., which was drawn from a 

 small or immature specimen, is as follows: Shell subperforate, ovate- 

 conic, thin, closely striatulate, obsoletely decnated with spiral lines, 

 under the lens ; whitish ; spire conic, rather acute. Whorls 0, a 

 trifle convex, the last subangulate in the middle, a little shorter than 

 the spire; columella a little receding ; aperture oval ; peristome sim- 

 ple, the columellar margin narrowly rerlexed, subappressed. Long. 

 21, diam. 10 mill. Aperture 10 mill, long., (i wide (Pfr., Proc. Zool. 

 Soc. 1846, p. 113). Locality unknown. 



A var. ,*, with the shell pellucid, buff, encircled by chestnut bands, 

 on the upper whorls interrupted into spots, is also described. This 

 variety is figured by Reeve, Conch. Icon. pi. 58, f. 389. Von Mar- 

 tens refers it to B. emeus Say. Probably it has nothing to do with 

 the typical zieyleri. 



In the Monographia, Pfeiffer gives the localities Central America 

 ( Largilliert) and Mexico ? (Liebmann). Pfeiffer furnished to Bin- 

 ney the shell figured as ziet/fcri in L. and F.-AV. Sh. N. A., p. 193, 

 f. 336. Carpenter records it from Mazatlan, as Ortlmlirnx zieyleri 

 (Max. fatal, p. 177). 



From the series before me, I am disposed to consider the Ma/atlan 

 zirylpri as identical with culifornlcus specifically; the description of 

 the latter here follows : 



B. ca//j'fi//rns Keeve (pi. 49, fig. 34). "Shell somewhat acumin- 

 ately ovate, rather thin, .M-uvely uinliilieated ; whorls li in number, 

 smooth; columella reflected; lip simple, fream color, encircled with 

 interrupted tran-\ T-e blue-black /.ones." 



Gulf must af Linn r < 'iili'i'm itin (Stearns), or perhaps mainland 

 coast of the (lulf; < '<i/ifr.'//(i (Hartweg, according to Keeve). 



/in/iiii its ctt/iY<>niirns KI.I:\ K, foneh. Icon. pi. .'>('<, f. 37H (Dee., 

 IMS). Pi i:., Monogr. iii, p. lil'. HIXXKY, Land and F.-W. Sh. 



N. A., i, p. Hill, f. ."I-") /ln/iitiii/us (/)/>/ in eus} ctillfnniirns DA 1. 1., 



1'roc. I'. S. Nat. Mus. xvi, 1 s'.). 1 ), p. C 1 1 SIIAKN-, iliid. x\ii, IMU, 



p. ir,:.. 



As stated above, this is apparently the much variegated extreme 



