118 THE NAUTILUS. 



ing 29-30 high, narrow, T-rail-shapecl ribs, flattened above, over- 

 hanging narrower, deep, nearly smooth channels ; and with marked 

 concentric imbrication, feeble on top of the ribs but articularly scaly 

 at their sides. The sculpture of the left valve is less pronounced, 

 hidden in the matrix, but apparently similar. Alt. 192, lat. 175, 

 diam. about 35 mm. The lateral edges are slightly defective, the 

 submargins very narrow. 



GENERAL NOTES. 



HOLOSPIRA MINIMA v. Martens In my opinion the northwest 

 Mexican forms referred to Holospira pfeifferi by Crosse and Fischer 

 and von Martens, are distinct from that central Mexican species ; 

 and as the varietal name minor is preoccupied (H. feres v. minor) ^ 

 the name minima of von Martens may be used. 



Dr. von Martens describes var. minima as " dense tenuiter 

 lamelloso-costata, length 11^ mm. only, 4 in the largest diameter; 

 aperture 2^ mm.; whorls 11, distinctly convex; color reddish- 

 yellow, the costa? white." The locality was not known, but the 

 figure shows the angular early whorls of the N. "W. Mexican form 

 described as a variety of pfeifferi by Fischer and Crosse, and I do 

 not doubt that the type came from that region. 



The shells collected at Hermosillo, Sonora, by Remond, are 

 larger, alt. 12^ to 13^, diam. of penult, whorl 4 mm. The riblets 

 are rather stout and crowded, though not quite as wide as their 

 intervals, and number 32 to 34 on the penultimate whorl. These 

 ribs, or many of them, have the peculiarity so strongly developed in 

 Urocoptis elliotti and some other species, of being hollow, and there- 

 fore easily broken down, showing only the edges of the two lateral 

 lamina?. There are 12^ whorls, and the color is nearly uniform. 

 The internal column is perfectly simple and the lumen of the whorls 

 is free from folds or lamella? of any sort. 



Specimens sent by Mr. Fred L. Button, exact locality not given, 

 are a little smaller, alt. 11-J- diam. above aperture 4 mm., have 1 1 to 

 1H whorls, and decidedly coarser ribs, 23 to 26 on the penultimate 

 whorl. 



Evidently the species is a variable one, and the varieties are 

 probably local. 



Tryon's figure of H. pfeifferi (Amer. Journ. of Conch, iii, pi. 15, 



