Contributions to the Knowledge of the Alpheid Shrimp 
of the Pacific Ocean 
Part II. Collection from Arno Atoll, Marshall Islands 1 
Albert H. Banner 2 
This paper reports upon a collection of snap- 
ping shrimp made by Dr. Robert W. Hiatt 
and Dr. Donald W. Strasburg, of the Univers- 
ity of Hawaii, at Arno Atoll in the southern 
portion of the Radak chain of the Marshall 
Islands. Under the sponsorship of the Pacific 
Science Board with funds from the Office of 
Naval Research, they visited Arno during the 
summer of 1950 as a part of a scientific team 
to investigate the total ecology of the atoll. 
One additional shrimp reported upon was 
collected by Dr. J. W. Wells of the same in- 
vestigation. 
This study of the snapping shrimp from 
Arno was initiated under a grant administered 
by the U. S. National Museum and the Pacific 
Science Board under a contract between the 
Office of Naval Research, Biology Branch, 
and the National Academy of Sciences, (NR 
160-175); some help in the final phases of 
the study was made available through a grant 
to the author from the National Science 
Foundation (NSF-G-1754). 
To avoid repititious synonymies and bibli- 
ographies in this series of papers, whenever a 
full citation for a species has been given in an 
earlier paper, by myself, reference is made to 
this citation. In this present paper reference 
is made only to Part I of these studies, describ- 
ing collections from the Mariana Archipelago 
1 Contribution No. 89, Hawaii Marine Laboratory. 
2 Department of Zoology and Entomology, Uni- 
versity of Hawaii, Honolulu, Hawaii. Manuscript re- 
ceived February 15, 1956. 
(Banner, 1956). Type specimens for the new 
species described in this paper will be depos- 
ited in the United States National Museum. 
Arno Atoll 
The nature and biology of Arno Atoll has 
been covered in a series of preliminary reports 
by members of the investigation team, pub- 
lished (in mimeographed form) in the Atoll 
Research Bulletin (issued by the Pacific Science 
Board), Numbers 3-11, 1951-1952. A com- 
prehensive book on these studies is now in 
preparation and specialized scientific reports 
are appearing in technical journals. 
Arno is an irregularly shaped atoll centered 
about 7° 05' N., 17° 40' E. and about 27 miles 
across its longest axis (Fig. 1). It consists of 
133 islands and islets, only a few of which are 
large enough to support human habitation. 
The outer margin of the atoll drops off steeply 
into waters of profound depth; within, the 
lagoon is estimated to be 100-200 feet deep. 
The ocean communicates with the lagoon 
through a series of passes, deep or shallow. 
The atoll lies in the belt of northeasterly trades 
and at the southern edge of the North Equa- 
torial Current, which may be replaced during 
some of the months of northern summer by 
the Equatorial Countercurrent. The ring of 
islands is surrounded on both inner and outer 
margins by coral reefs of varying vitality and 
breadth, depending upon conditions of wind, 
surf, sediment, etc. 
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