PLANISPIEA. 285 



Halmahera. Uufigured. Near P. zonaria. 



P. THETIS Pfr. is reported from Halmahera by Strubell, who 

 believes it a distinct species from P. exeeptiuncula. 



Section Cristigibba Canefri. 



To this section belongs H.purpurostoma Le Guillou, described in 

 the Manual Vol. VI, p. 177. It is evidently closely allied to H. 

 dominula, deaniana, corniculum and the following. 



P. MACGREGORI Hedley. Vol. IX, pi. 12, figs. 13, 14, 15. 



Shell umbilicated, discoidal, thin, translucent ; color reddish- 

 brown above, lighter beneath, peristome bright lilac, interior of 

 shell subnacreous, iridescent, gleaming bluish-white ; whorls 4, 

 rounded, the earlier gradually, the last rapidly increasing, last 

 descending considerably and gradually at the aperture and furn- 

 ished with the gibbosity characteristic of the genus; sculpture 

 oblique, flat-topped, costee whose shallow interstices contain two or 

 three fine radiating stride, both costse and striae are crossed by 

 minute spiral grooves ; apical whorl sunken, smooth ; suture deeply 

 impressed ; aperture diagonal, lunate, peristome widely expanded 

 above, reflected below, margins approaching, connected by a thin, 

 transparent callus, columellar margin expanded over a quarter of 

 the umbilicus ; the latter narrow, deep, showing every revolution of 

 the spire, margins abruptly rounded. 



Diarn. maj. 28, min. 21, alt. 12 mill. (Hedley. ,) 



Village of Arpiana, St. Joseph River, New Guinea (Hedley.) 



Cristigibba macgregori HEDLEY, P. L. S. N. S. W. (2), vi, p. 82, 

 t. 10, f. 17-19 (shell) ; ibid. p. 687, t. 38, f. 6 (jaw) and t. 39, f. 12 

 (dentition). 



Dead shells were seen in abundance, animals were purchased 

 from the natives. Dedicated to Sir William Macgregor, M. D., K. 

 C. M. G., whose zeal for science has greatly increased the world's 

 knowledge of the Papuan fauna and flora. Type in Queensland 

 Museum. (Hedley. ,) 



Section Trachiopsis Pilsbry. 



P. DENTONI Ford. PI. 51, figs. 44, 45, 46. 



Shell small, depressed, umbilicate, rather thin, shining ; color 

 corneous-brown, encircled above the periphery by a faint brown zone. 

 Surface under a lens presenting a roughish appearance, caused by 



