114 ANOSTOMA. 



palatal folds, with a minute upper suprapalutal. Another, received 

 by Swift from Bernard!, has in addition a punctiform angle lamella, 

 and the lower one of the suprapalatal folds. 



Still another shell (pi. 6, figs. 48, 49) labeled "near Rio del 

 Norte, Brazil," is more acutely carinated, with teeth like the speci- 

 men last mentioned. 



2. Group of A. ringens. (Section Ringicella Gray.) 



Ringicella GRAY, P. Z. S., 1847, p. 173, for A. ylobulosa. Tomo- 

 gerina JOUSSEAUME Bull. Soc. Zool. de France, 1877, p. 312, type 

 A. globulosum Lam. 



A tendency toward the formation of a sutural channel may be seen 

 in CycJodontina and Hyperaulax, though it is not closed over in these 

 forms, as it is in Rinyicella. 



A. RINGENS (Linne). PI. 5, figs. 27-29, 32-36 ; PL 7, figs. 55-61. 



Shell biconvex, solid, brownish -yellow, with a dark-brown band 

 above the periphery, another bordering the suture ; the base rather 

 sparsely marked with irregular reddish -brown spots and usually hav- 

 ing a dark stripe below the basal suture. Surface hardly shining, the 

 last whorl densely corrugated in zigzag pattern, but sometimes this 

 sculpture is almost obsolete. Whorls 4|, the last carinated at the 

 periphery, having three deep, dark-colored grooves and one small 

 one behind the lip. Aperture subhorizontal, elevated above the 

 periphery, obstructed by six white teeth : two strong lamellas upon 

 the parietal wall, the parietal lamella compressed, curving upward 

 within, the infraparietal stouter and straight ; outer lip broad, ex- 

 panded and reflexed, white, its upper end perforated by an oval hole ; 

 outer margin with four long folds within, of which the columellar 

 and the lower and upper palatal are subequal, the inner end of the 

 latter being strongly bent upward ; suprapalatal fold smaller and 

 oblique, almost transverse; above it may be seen a small upper 

 superpalatal fold, which has united with the angle-lamella to form 

 the wall of the respiratory foramen, perforating the end of the lip. 



Alt. 13, diam. 25 mill. 



Alt. 1<H. diam. 18 mill. 



Brazil : Rio Negro (Anthony, in coll. A. N. S.). 



Helix ringens LINNK, Syst. Nat. (10), p. 769, 1758 (exclusive of 

 references); cf. HAM.KV, Ipsa Linn. Conch., p. 363. Anostoma 



