38 SPIRAXIS. 



(Oct., 1849). REEVE, Conch. Icon, v, pi. 84, f. 624 (Dec.,. 

 1849). 



The original description applies well to the form figured 

 (fig. 46) and described above, from the only living perfect 

 Sigmataxis of the type lot, except that it measures somewhat 

 less, and has fewer whorls. There is an obvious error in 

 Adams' measurements of this species, and probably the num- 

 ber of whorls is >also wrongly stated by him, or 'counted on 

 another shell than that measured. The type lot contains two 

 Opeas goodalli, one small Varicella and several of the form 

 here described as S. pauperculus. It is very closely related 

 to S. laviusculus Ad., but it seems to be specifically distinct 

 by the more swollen last whorl and the closer grooves of the 

 spire. 



I figure also a typical shell from the Academy collection, 

 probably received from Adams, and measuring 6.2 x 2 mm., 

 with 5% whorls (pi. 4, fig. 51) . Also a large specimen from. 

 Long mountain (Henderson coll.), measuring 7.5 x 2 mm., 

 aperture 2.8 mm., with 6!/2 whorls. There are about three 

 pale brown streaks on each of the later several whorls (fig. 

 50). 



Arango introduced pauperculus in his Cuban Fauna on 

 account of an alleged identity with B. pumilus Pfr., which 

 is a form or synonym of Opeas goodalli (see vol. XVIII, p. 

 202). This error was probably due to Adams' failure to 

 discriminate between these two small forms in sending out 

 material. His idea of pauperculus was evidently not clear,, 

 and included more than one species. 



38. S. PERPLEXUS (C. B. Adams). PI. 4, figs. 41, 42. 



' * Shell ovate-fusiform, much elongated ; almost transpar- 

 ent, pale yellowish brown, with transverse, moderately curved 

 lines of dark brown, of which the last colors the labrum, three 

 to four on each whorl, wanting on the upper whorls, and 

 scarcely perceptible at and above the middle of the spire; 

 with fine not crowded transverse striae ; lines, which indicate 

 the varices that are coincident with the brown stripes, scarcely 

 distinguishable from the striae; apex subacute, with nearly 



