DRYMJ2US, MEXICO AND CENTRAL AMERICA. 61 



like D. papyraceus, having quite the color and pattern of some forms 

 of that Brazilian species. 



D. attenuatus is closely allied to D. costaricensis, but differs some- 

 what in the pattern of coloring, and in being more elongated than 

 the typical form of the latter species. Costa Rican specimens col- 

 lected by Gabb practically efface this distinction, however, having 

 the long form of attenuatus and the color-pattern of costaricensis. 

 The spotless form (var. concolor Martens, pi. 2, fig. 14) occurs with 

 the typically colored form. 



Dr. von Martens writes: The brown stripes are nearly perpendic- 

 ular, often interrupted near the suture, and ordinarily less numerous 

 in the last whorl than in the preceding ones ; in some specimens they 

 are entirely wanting in the last whorl, these forming a transition to 

 the white variety. In a few specimens the stripes become broader 

 and look rather like those of 0. serperastrion var. paivanus ; but the 

 shell is easily to be distinguished from that of Otostomus serperastrum 

 by its more attenuated shape and the much thinner, conspicuously 

 spirally-twisted columella. The apex of the shell and the inside of 

 the aperture are in some specimens yellowish. The var. pittieri, 

 from Costa Rica, differs in the shell being smoother and rather yel- 

 lowish, the streaks not interrupted ; it has the aperture formed ex- 

 actly as in typical attenuates. 



Var. VARICOSUS Pfeiffer. (PI. 15, figs. 36, 37; pi. 2, figs. 9-11). 

 A little more ventricose ; alt. 36-37, diam. 16-18, length of aperture 

 17-19 mill. 



Bulinnis varicosus PFR., P. Z. S. 1851, p. 256; in Martini & Chem- 

 nitz, Syst. Conch. -Cab. ed. 2, Bulimus, p. 83, pi. 30, figs. 7, 8 ; 

 Monogr. Helic. Vivent. iii, p. 326 Bnlimus kefersteini var. /^, PFR. 

 Novit. Conch, iii, pi. 76, fig. 9. Otostomus attenuatus var. varicosus 

 MARTENS, Biologia, p. 216, pi. 13, f. 10. 



Var. PITTIERI von Martens (pi. 2, fig. 16). Lightly striatulate 

 and with scarcely noticeable spiral lines, yellow, shining, with con- 

 tinuous, undulating widely separated streaks. Long. 30, diam. 13, 

 apert. long. 15, diam. 8 mill. 



Bulitnus attenuatus ANGAS, P. Z. S. 1879, p. 478 0. attenuatus 

 v. pittieri VON MART., Biologia, p. 216, pi. 16, f. 1. 



S. W. Costa Rica : Alto de Mano Tiyre, near Terraba, 690 metres 

 above the sea (Pittier); Central Costa Rica: Dota, a high hill-region, 

 south of San Jose (Gabb). 



