PARTULA, TAHITI. 195 



There is usually more or less pale streaking of the dark 

 ground on the last whorl; the reverse of the lip and the 

 border of the umbilicus are also pale. Several examples seen, 

 one of them received from Dr. Pfeiffer. All are dextral. 

 Judging 'by the lots before me, this form occurs in the same 

 colonies with the following color phases. 



Color-form TRILINEATA Pease. PI. 25, figs. 14, 15. "Cream 

 color or yellowish horn-color, the spire usually reddish-brown, 

 last whorl striped irregularly with brown, and encircled by 

 three dark reddish-'brown lines or 'bands; suture margined 

 with white "(Pse). In the typical lot of trilineata received 

 from Pease the spire is fleshy brown in two examples (typical 

 -coloration) ; clear corneous in two; and the other two have 

 some whitish and faint 'brown markings on a fleshy- corneous 

 ground. Four of the shells are 3-banded, like fig. 14, 15, one 

 has only a wide chestnut 'belt, and is conspicuously streaked 

 with brown, and the sixth is a typical nodosa in color. 



A lot from Grarrett consists of ( 1 ) ordinary dark P. nodosa ; 

 (2) one sinistral shell (fig. 16) with normal trilineata color- 

 pattern. Garrett states "about one in two hundred is sinis- 

 tral ") ; and (3) pale shells with the spire corneous, last I 1 /-* 

 whorls cream-colored with a profusion of corneous and cor- 

 neous-brown streaks which do not reach to the suture; aper- 

 ture typical (pi. 25, fig. 17, color- form pallidior). 



14a. P. N. L.EVA, n. n. PL 25, figs. 18, 19. 



' ' The shell is blunt in shape and the spire is short ; the lip 

 is quite thick, and is usually provided with a well-developed 

 tooth upon the columellar side, and there is also a tooth upon 

 the wall of the aperture. The surface of the shell is smooth 

 and slightly polished, and there are no deep longitudinal fur- 

 rows. About 57 per cent of these snails are well represented 

 by fig. 18. The ground color is a light horny-yellow streaked 

 longitudinally with darker brown, in addition to which there 

 are two dark-brown whorl-stripes and a white whorl-stripe 

 adjacent to the suture of the spire. In about 43 per cent 

 the dark-brown whorl stripes are either absent or veiy faint, 



