HELIX-PLANISPIRA. 293 



less concealed by the columellar lip, which is in the deaniana very 

 narrow. It differs from corniculum in having the band not con- 

 tinued upon the lip ; the inner whorls not rosy, the baso-columellar 

 lip much more arcuate, etc. 



H. DOMINULA Tapparone Canefri. PI. 68, figs. 79, 80, 81, 82. 



Shell umbilicated, discoidal, shining, obliquely striatulate and 

 most obsoletely costulate, rosy-reddish, rarely with a brown zone 

 above ; spire plano-convex, the apex subimmersed ; whorls 4, a lit- 

 tle convex, and separated by profound sutures ; last whorl large, 

 very obscurely subangular at the periphery, descending in front, 

 subconstricted behind the aperture and obliquely swollen on the 

 base; base a little convex, and having a little-dilated, perforating 

 umbilicus. Aperture rotund-lunate, very oblique, ample, the throat 

 pearly white ; periatome expanded, margins converging, approxi- 

 mating, the right regularly lunate, broadly expanded, basal little 

 incurved and narrow, columellar short, dilated, and above the um- 

 bilicus narrowly reflexed. Largest example, alt. 13, greater diam. 

 28, lesser 23 & mill. Smallest example, alt. 12, greater diam. 21, les- 

 ser 18 mill. (Tapp. Car,.) 



On the Rivers Fly and Katau, Southern New Guinea. 



H. dominula TAPP. CAN., Ann Mus. Civ. di Genova, xix, 1883, 

 p. 178, t. 4, f. 8-11, and anatomy, t. 7, f. 4 ; t. 9, f. 5, 14. 



This species has much affinity in form to H. corniculum H. & J., 

 but is very distinct and easily recognized by its generally larger 

 size, the convexity of the spire in the new species, which becomes 

 only flat on the last whorl, but is slightly concave in the middle ; 

 by the great tumidity of the last whorl behind the aperture and its 

 less deflection in front ; and finally by the smaller size of the umbili- 

 cus, which differs from that of H. corniculum, in being always at 

 least one-third covered by the columellar margin. (Tapp. Can.) 



The following variations are noted by Tapparone Canefri : 



Form a. Entire shell, including peristome, white. Alt. 12, 

 greater diam. 27, lesser 22 i mill. 



Form b. Shell white, peristome rosy. Alt. 12, greater diam. 26, 

 lesser 21 J mill. 



Form d. (pi. 68, fig. 81.) Shell larger, more depressed, the 

 aperture wider, white with a wide brownish chestnut zone above, the 

 peristome broadly expanded above, bright rose-colored. Alt. 14, 

 greater diam 31, lesser 25 mill. River Fly. 



