STROPHOCHEILUS-THAUMASTUS. 51 



I have given Philippi's words above, and on pi. 26, f. 90, a copy of 

 his figure. Reeve's B. consimilis (pi. 26, fig. 89) is absolutely syno- 

 nymous. See under next species for comparisons. 



S. ACHILLES Pfeiffer. PL 26, figs. 84-88. 



Shell im perforate, ovate-elongated, rather solid ; tawny brownish, 

 more or less profusely obliquely streaked ivith dark brown and white 

 (the streaks spreading at suture), under a thin yellow cuticle, and 

 showing a more or less distinct light girdle at the periphery.. Surface 

 inconspicuously wrinkle-striate, decussated by incised spiral lines, 

 rather- obsolete on last whorl ; the nepionic shell densely and finely 

 rib-striate, the strise rather wavy. Spire produced, conic, the apex 

 very obtuse, entire. AVhorls 6*, first planorboid, several following 

 hardly convex, the latter two whorls gently convex with more im- 

 pressed suture, which is slightly marginated or not, and generally 

 ascends somewhat in front. 



Aperture small, narrowly ovate, fleshy inside; peristome white, 

 simple, obtuse, slightly thickened inside ; columella deeply indented, 

 having a slightly convex, entering fold above. 



Alt. 57, diam. 25? ; alt. of aperture 26 mill. 



"Banks of the Amazon " (Mus. Cuming) ; Piracicaba, on an upper 

 affluent of the Tiete, tributary of the Parana River, Prov. S. Paulo, 

 Brazil (Nehring). 



Bullmus achilles PFR., P. Z. S., 1852, p. 137 ; Conchyl. Cat., p. 

 247, pi. 66, f. 9 ; Monogr., iii, 378. MARTENS, Couchol. Mittheil., 

 iii, Dec., 1889, p. 11, pi. 40, f. 8. B. achilles var. Nehringi MAR- 

 TENS, t. c., p. 12, pi. 40, f. 9, 10. 



I am disposed to consider this merely a stouter form of S. larailll- 

 erti Phil. ; but having no typical examples of that species before 

 me, it may be best, until the identity is proven, to let achilles stand 

 as a species. The locality given, " Banks of the Amazon," rests 

 upon the insecure basis of a Cumingian label. 



Var. nehringi Martens. PI. 26, figs. 87, 88. 



Ground-color lighter ; peripheral light band distinct. This form 

 has probably no varietal status. It is from Piracicaba, Prov. S. 

 Paulo. It will be noted that S. largillierti, which is very nearly 

 allied, if not identical, is from the adjacent province, Sta. Catarina. 



S. achilles is at all times a smoother shell than S. porphyrius, has 

 a different pattern of sculpture on the apical whorls, and is not um- 

 bilicate, although occasional specimens show a very slight chink. 



