MALACOLOGIA, 1965, 3(2): 235-262
MARINE EUTHYNEURAN GASTROPODA FROM ENIWETOK ATOLL,
WESTERN PACIFIC 1
Ernst Marcus2 and J. B. Burch^
ABSTRACT
This study is based on a collection of marine euthyneuran mollusks made by
the second author at Eniwetok Atoll , Marshall Islands, during February-Apr il,
1960. Seventeen species were collected, of which 5 are described in this paper
as new species. The new species are: Haminoea musetta, H. linda, Chromo-
doris briqxm, Herviella mietta and Onchidella eveltnae. Of the other 12 species,
the distribution of 7 of them extends eastward from the western Indian Ocean (2
also occur in the Red Sea) to Eniwetok or farther east; 2 species are circum-
tropical or circumsubtropical; 2 species are known only from the western
Pacific; and 1 species occurs from Eniwetok westwards into the eastern Indian
Ocean. The relative uniformity of the western Indopac if ic reef fauna is indicated
by the fact that 9 (or over 50%) of our species are known to range from the
western edge of the Indian Ocean to the western or central Pacific. The genus
Herviella seems to be confined to the western Pacific. Thenotogaeic occurrence
of an Onchidella with a ventral recurrent limb of the kidney and a cuticular
stylet in the diverticulum of the penial pouch is remarkable.
Eniwetok Atoll comprises a group of
some 30-odd coral islands in the western
Pacific. Eniwetok is one of several such
atolls which make up the Marshall Islands
of Micronesia. During the months of
February-April, 1960, the second author
and Dr. William H. Heard collected
mollusks on 4 islands of Eniwetok Atoll.
The present report is based on the 17
species of euthyneuran gastropods col-
lected at that time. All specimens,
except representative series sent to the
University of Hawaii and the University
of Sao Paulo, are now in the collections
of the Museum of Zoology, University
of Michigan.
Grateful acknowledgement is made to
the United States Atomic Energy
Commission for supporting the study of
the second author at Eniwetok by pro-
viding travel funds, logistical support and
use of the facilities of the Eniwetok
Marine Biological Laboratory. The
cooperation of the U. S. A. E. C. Eniwetok
Field Office, Task Group 7.1, and Holmes
and Narver, Inc., greatly facilitated the
field collecting. A note of gratitude is
due to Dr. I. Eugene Wallen, U.S.A. E. С,
Dr. Robert W. Hiatt, University of
Hawaii, and Prof. Henry van der Schalle,
University of Michigan, for promoting
these studies, and to Dr. William H.
Heard, Florida State University, for
assistance while at Eniwetok. Acknow-
ledgement is also due Mrs. Eveline du
Bois-Reymond Marcus for assistance to
the senior author and for preparing the
illustrations.
MATERIALS AND METHODS
The animals reported on here were
BioStor
