MOLLUSCA FROM JUAN FERNANDEZ AND EASTER ISLAND 231 
and 0,3 mm in breadth, it contained 80 rows, each consisting of a median tooth, 
5 lateral and 12 marginal teeth on each side, the laterals having subequal endo- 
and ectocones, the inner marginals with simple ectocones, the outer ones with 
bicuspid or tripartite ectocones. In A. marmoredla the radula (fig. 9) measured 
about 0,7 mm in length and about 0,2 mm in breadth; its rows were about it, 
and in each row there were in one specimen I median + 6 lateral + 8 marginal 
teeth on each side, all of the same shape as in A. helicophantoides; in another 
specimen there were I + 5 + 13 teeth in half a row, the marginals of a different 
shape (one, tooth 14, even geminous); the median tooth in this second specimen 
was considerably smaller. 
From the specimen preserved in alcohol it could be stated, that the foot 
is furnished with two lateral grooves as well as a caudal mucous pore; thus 
the reference of the genus to the fam. Endodontidae, which PILSBRY maintains, 
is verified. 
Stephanoda quadrata Férussac. Pl. 9, figs. 33—35. — Masatierra (Aug. 
1917): the Yunque quebrada, lower part, a few sps., d. 4. — Beneath Damajuana, 
about 300 m, 4 sps., d. 6. — Piedra -Agujeriada Valley, 4 sps., d. 6. — Salsi- 
puedes Ridge, on ferns and beneath leaves, about 350 m, many sps., d. 5,2. — 
Masatierra (No. 605), 2 sps., d. 3,5 mm. 
This species varies somewhat in painting as well as in shape, inasmuch 
as its aperture may be more or less depressed, and generally it is more so 
than represented on REEVE’s fig. (Conch. Icon. 7, fig. 619). Also E. A. SMITH 
(1884, Proc. Zool. Soc. London, p. 279) finds some difference between the 
»Challenger» specimens and those in CUMING’s collection. I give some figures 
of the present species on plate 9. 
Stephanoda tessellata Mihlfeldt. — Masafuera, among ferns, 2 sps., d. 
3,4 mm (17/3 1917). This species was not found by the Swedish expedition in 
Masatierra from where it is known before (Juan Fernandez; cf. TRYON, Man. 
of Conch. III, 1887). 
Remarks on the Genus Stephanoda. 
The Juan Fernandez species of this genus have not been studied with 
respect to their anatomy, but their shell characteristics evidently announce their 
reference to the S. American genus Stephanoda. None of the typical forms has 
been examined for inner anatomy. To the same genus, however, a small shell 
from Kerguelen Island, S. (Amphidoxa) hookeri Reeve, has been referred, the 
anatomy of which has been described by SCHAKO & PFEFFER (1877; cf. PILSBRY 
1894). This is, however, so essentially different from that of the typical and 
Juan Fernandez forms, that the species named must be kept apart from the true 
Stephanodas. 
As to the external appearance of S. guadrata it may be stated that the 
foot: carries on each side two longitudinal furrows extending throughout its 
length, as well as a mucous pore in the posterior end; the foot sole is undivided 
longitudinally, showing transverse wrinkling only, no longitudinal furrows as is 
