222 NILS HJ. ODHNER 

*Arca angulata King. 
26 man (9/4 F017): 
Masatierra, 60—70 m, on a stone, 2 sps., max. I. 
Ervilia producta n. sp. Pl. 8, figs. 11, 12. — Shell elliptical, rather 
compressed, not inflated, with small papilliform submedian apices; anterior, as 
well as dorsal, margin straight, inferior -gently curved; anterior end of shell 
narrowly rounded, posterior part somewhat more produced and indistinctly set 
off as a cauda by means of a faint sinuation on its under side; posterior end 
with sharper curve of outline than anterior one. Sculpture consisting of fine 
concentric striae over the whole shell; its posterior (caudal) portion finely 
radially striated. Colour white, with indistinct brown radiating stripes and flames, 
mostly on the anterior half of the shell; interior white with the brown painting 
shining through and with a faint nacreous gleam. Max. dimensions: |. 8,4, h. 5, 
crass. 2,9 mm. 
The sculpture of this shell somewhat recalls that of 4. dzsculpta Gould 
(cf. LYNGE 1909, pl. IV, figs. 14—16), but it lacks the striae on the anterior 
part of the shell and is more produced and less inflated. It was collected at 
Masatierra, 20-35 m, Corallina bottom, many sps., max. |. 8,4 mm (17/4), and 
in 30—45 m, same bottom, I sp., |. 7,3 mm (?8/s). 
Chama imbricata Broderip. — Masatierra, 40—109 m, rather common, 
according to the notes of Mr. BACKSTROM; one living specimen collected, max. 
diam. 60 mm. A good characteristic of this species is the sculpture of the 
cardinal teeth the surfaces of which are not rifled as usual, but furnished with 
regular series of tubercles (each series corresponding to a normal rifle). In the 
animal the left umbo is greatly protracted, and the foot is compressed and 
squarely dilated. The species is widely distributed throughout the Pacific Ocean 
(in R. M. from Keeling Island and Tahiti; also from Mauritius and Japan; 
cf. REEVE). 
*Venerupis fernandeziana Stempell. — Masatierra, 20—35 m, sand with 
Corallina, many sps., max. |. 12,5 mm, '1/4. STEMPELL, who described this 
species in 1899, states its maximum length to be 7 mm only. 
3. Gastropoda. 
Acmaea juanina n. sp. Pl. 8, figs. 1, 2. — Shell ovate, of moderate 
height, its apex in the first third of its length; anterior and lateral slopes straight, 
posterior one a little convex. Sculpture consisting of concentric striae and 
radiating ribs of alternating strength, 11 principal ones with finer ones in the 
interstices. The coarsest ribs (4 in front, I on each side and 5 behind the apex) 
as well as the apex dark-violet in colour, olive-brown towards the periphery 
like the intervening ribs; ground white. Interior white, with a chestnut centre 
and an olive-green margin. Dimensions: |. 13,2, br. 10, h. 4,5 mm. 
This species seems to be akin to A. albescens Philippi from Central Chile, 
or to A. carpenteri Pilsbry from the West Indies (cf. PILSBRY, Man. of Conch., 
