248 



GARTH, HAIG, AND KNUDSEN 



SUMMARY 



The Anomura presently known from Enewetak Atoll 

 comprise 76 species, representing 29 genera and 10 fami- 

 lies. Of this number, 48 species are new to Enewetak, and 

 43 are new to the Marshall Islands as well. The family 

 Diogenidac is best represented, with 27 species in seven 

 genera; the family Porcellanidae has 17 species in three 

 genera. Expressed in percentages, of the 76 species listed, 

 63.15% are new to Enewetak, and 56.57% are new to the 

 Marshall Islands. The Diogenidae contain 35.52% of the 

 species and 24.13% of the genera; the Porcellanidae con- 

 tain 22.36% of the species and 10.34% of the genera. 



The Brachyura presently known from Enewetak Atoll 

 comprise 291 species, representing 115 genera and 16 

 families. Of this number, 218 species are new to 

 Enewetak, and 170 are new to the Marshall Islands as 

 well. The family Xanthidae is best represented, with 155 

 species in 49 genera; the family Portunidae by 36 species 

 in nine genera; the family Majidae by 23 species in 13 gen- 

 era; and the family Grapsidae by 21 species in 10 genera. 

 Expressed in percentages, 74.91% of the 291 species are 

 new to Enewetak and 58.42% are new to the Marshall 

 Islands as well. The Xanthidae contain 53.26% of the spe- 

 cies and 42.60% of the genera; the Portunidae contain 

 12.37% of the species but only 7.82% of the genera; the 

 Majidae contains 7.90% of the species and 11.3% of the 

 genera; and the Grapsidae contain 7.22% of the species 

 and 8.70% of the genera reported. (The number of species 

 and genera new to Enewetak and the Marshall Islands 

 would be even greater had not many been reported in pub- 

 lications in which the crabs, often identified by the first 

 writer, were not the primary interest of the investigator 

 who reported them but incidental as the hosts of isopod or 

 copepod parasites or as agents of bioerosion of corals.) 



Because so large a number of brachyuran crabs remain 

 identified to genus (35) or even to family (3) only, no 

 meaningful comparison with other crab faunas is fxjssible 

 at this time. This shortcoming will be rectified when the 

 Enewetak crabs arc elaborated a family at a time and the 

 new or obscure species described and illustrated. The defi- 

 ciency is particularly apfjarent in the family Parthenopidae, 

 of which no comprehensive review has been made since 

 the Siboga report (Flipse, 1930). 



ACKNOWLEDGMENTS 



The generous assistance in the identification of rare or 

 obscure species of Brachyura by specialists who visited the 

 Hancock Foundation while the first author's studies were 

 in progress, or to whom specimens were later sent, is 

 gratefully acknowledged. These include R. S. K. Barnes, 

 the genus Macrophtbalmus; I. Gordon, the single pinnoth- 

 erid; D. J. G. Griffin, the genus Ciiclograpsus and the fam- 

 ily Majidae; M. Takeda, the Pilumninae; T. Sakai, the 

 Oxystomata; R. Serene, the Trapeziinae; and W. Stephen- 

 son, the Portunidae. The second author's studies on the 

 Anomura were facilitated by Susan L. Brunenmeister, who 



provided information on her Enewetak collections; Patsy 

 A. McLaughlin, who sent a portion of this collection for 

 the verification of a few identifications; and Philip Helfrich, 

 who provided a copy of the Brunenmeister report (Brunen- 

 meister, 1975). For the thalassinoids, Michele de Saint 

 Laurent and L. B. Holthuis helped with identifications and 

 R. B. Manning with information. The authors are most 

 grateful to the late Dennis M. Devaney and to Ann Fielding 

 for providing information concerning Enewetak specimens 

 in Bishop Museum collections, and most of all, to the many 

 collectors whose records have been used with their permis- 

 sion in cases where it was possible to contact them. 



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