120 OXYSTYLA, MEXICO, ETC. 



Monatsber. Akad. Wiss. Berlin, 1863, p. 542 ; Malak. Blatt. xii, p. 

 42 (1865). PFR. Monogr. Helic. Vivent. vi, p. 199 FISCH. & 

 CROSSE, Miss. Scient. Mex., Mollusca, i, p. 447 PILSBRY, Proc. 

 Acad. Nat. Sci., Phila. 1891, p. 317 Orthalicus princeps STOLL, 

 Guatem. Reisen, p. 430. Ortcdichus ferussaci MARTENS, Biol. 

 Centr. Amer. p. 184, pi. 10, f. 8-10 (exclusive of South American 

 localities and references). 



Not 0. ferussaci MARTENS, Binnenmoll. Venez., nor of STREBEL, 

 Beitr. Mex. Land- und Siisswasser-Conchylien, = 0. maracaibensis 

 Pfr. 



11 This species is chiefly characterized by the combination of streaks 

 and spiral bands. Some specimens come very near to the young 

 state of 0. princeps ; and others to 0. undata Brug., from the Carib- 

 bean islands and Florida, which, however, is ordinarily more ellipti- 

 cally elongated, and has paler, rather bluish-livid, bands and streaks." 



The description given above is that of Dr. von Martens, and fig- 

 ures 16 and 17 represent the typical specimens figured by him. Figs. 

 14, 15 are specimens from Salinas Bay, Costa Rica, where it occurs 

 with 0. princeps. Fig. 13 represents a shell from Shkolak, Yucatan. 



In my opinion, the shells from Colombia and Venezuela referred 

 to ferussaci by von Martens and Strebel are forms of 0. maracaiben- 

 sis Pfr., the large series before me practically demonstrating this 

 position. In fact, 0. ferussaci belongs to an appreciably different 

 stock, that of 0. princeps ; agreeing with that species in the smooth- 

 ness of the surface, rarity of black varices (not more than one or two 

 on the whole shell, and those usually remote from the lip-edge), and 

 in contour. It is sometimes a mere matter of opinion whether a 

 given specimen be referred to princeps or to ferussaci. It is perhaps 

 better as a sub-species of princeps than as a distinct species. 



In its retention of spiral bands in the adult, 0. ferussaci shows a 

 more primitive condition of the color pattern than 0. princeps. 



VAR. TRICINCTA (von Martens). PI. 18, figs. 4, 5, 6 ; pi. 17, fig. 18. 



Form as in ferussaci or somewhat more slender, the aperture less 

 than half the length of the shell ; yellow or brownish below, paler 

 above, with three brown spiral bands, the upper one often faint, 

 almost wanting ; longitudinal streaks typically wanting, but some- 

 times present though very faint ; apex blackish ; dark varices few or 

 one, usually none on the latter half of the last whorl ; peristome 



