MOLLUSCA FROM JUAN FERNANDEZ AND EASTER ISLAND 253 
Though the external appearance of this species — shape, colour, and 
sculpture — are extremely like those of Stephanoda tessellata (only relative 
dimensions of whorls and umbilicus are different), its apertural equipment (which 
is rather difficult to discern except in strong penetrating light) proves it to be 
a member of the Zhaumatodon- group of Lxdodonta; the most akin species 
may perhaps be /, occulta from Masatierra described above. 
Only one specimen of this species was collected. 
Succinea masafuerae n. sp. Fig. 24. — Shell extremely thin and fra- 
gile, ovate, with a minute papilliform spire only a sixth of the shell height, 
well-rounded whorls, and a large, ovate aperture occupying °/¢ of the shell 
height. Colour yellowish horn-green. Sculpture: dense and rather marked lines 
of grouth together with a fine crossing striation very similar to that of S. zer/a 
(see above). Dimensions: height 6,5, breadth 4 mm; whorls 2 */s. 

Fig. 23. Endodonta skottsbergi n. sp. X% 14. 
Fig. 24. Succinea masafuerae n. sp. X 4. 
The crossed striation is a character which this species shares with 5S. 
texta from Masatierra, which thus may be considered as its nearest ally. The 
present form is however thinner and lighter in colour; further its shape is 
different, inasmuch as the spire is much shorter and not produced like that 
of S. fexta. These characters clearly show the specific distinctness of the pre- 
sent form, of which unfortunately only four much defective specimens were 
found. 

