ECHINODERMATA OTHER THAN HOLOTHUROIDEA 



283 



Mithrodiidae 



The family Mithrodiidae is newly recorded from 

 Enewetak and the Marshall Islands, on the basis of a 

 widespread Indo-West Pacific species, Mithrodia clavigera. 



Echinasteridae 



Echinaster luzonicus is known from Enewetak and else- 

 where in the Marshall Islands (A. H. Clark, 1952). 

 Lawrence and Guille (1982) recorded the dry weight 

 organic composition of this sea star and other echinoderms 

 from Enewetak. 



ECHINOIDEA 



Cidaridae 



The cidarids are represented by two species. Eucidaris 

 metulaha has been found in shallow water at Enewetak 

 and Rongerik and to a depth of 88 m at Bikini (A. H. 

 Clark, 1952). Specimens of Chondrocidaris gigantea were 

 collected from approximately 130 m and confirm an earlier 

 record from Bikini based on one spine (A. H. Clark, 

 1952). This species has been observed at Kwajalein by 

 divers (S. Johnson, personal communication). Additional 

 cidarid species were observed and photographed in deeper 

 waters (to 360 m depth) off the seaward side of Enewetak 

 during submersible dives in 1981. 



Echinometridae 



Three genera and species of Echinometridae occur at 

 Enewetak. Four of the species have been reported from 

 Enewetak previously, and these range widely in the Indo- 

 West Pacific. The fifth species, Heterocentrotus mawmil- 

 Jatus, is now known from the atoll on the basis of one 

 specimen. This species ranges from the Philippines to 

 Hawaii and the Tuamotus. Banner and Banner (1960, 

 1968) reported collecting the caridean shrimp Athanas dor- 

 salis from large Heterocentrotus sea urchins at Enewetak 

 and elsewhere. They also reported another alpheid, A. 

 indicus, associated with burrowing sea urchins in the genus 

 Echinometra. 



Diadematidae 



The Diadematidae includes Diadema sauignyi, a widely 

 distributed Indo-West Pacific species, newly recorded from 

 the Marshall Islands. Echinothrix calamahs and E. diadema 

 are also known from Enewetak and others of the Marshall 

 Islands (A. H. Clark, 1952, 1954). 



Parasaleniidae and Temnopleuridae 



One representative of both the Parasalenidae and Tem- 

 nopleuridae (Parasalenia gratiosa and Mespilia globulus, 

 respectively) has been reported at Enewetak and elsewhere 

 in the Marshall Islands (A. H. Clark, 1952j. These species 

 are widespread in the Indo-West Pacific. 



Toxopneustidae 



The Toxopneustidae has three Enewetak species; 

 Cri/techinus uerruculatus and Tripneusfes gratilla have been 

 previously reported from Rongelap, Bikini (A. H. Clark, 

 1952), and Enewetak (Highsmith, 1981); Tripneustes gra- 

 tilla is recorded only from Enewetak by A. H. Clark 

 (1952). Toxopneustes pileolus is newly recorded from the 

 atoll and the Marshall Islands. 



Schizasteridae 



Among the irregular echinoid families, there is evi- 

 dence that at least one, possibly two, members of the 

 Schizasteridae occur in the lagoon substrata (V. Fry, per- 

 sonal communication). 



Fibulariidae 



The Fibulariidae were known at Enewetak by two 

 species each of Echinoc^/amus and Fibularia reported by A. 

 H. Clark (1952). A third species of £c/iinocyamus, £. 

 crispus, is a new record. This may be a senior synonym 

 for E. elongatus, a species recorded from Bikini by A. H. 

 Clark (1952). 



Spatangidae 



The only spatangid known from Enewetak is Maretia 

 planulata (as M. ovata) from Enewetak and Bikini by A. H. 

 Clark (1952). This is one of the most common echinoids in 

 certain areas of the Enewetak Lagoon (V. Fry, personal 

 communication). 



Brissidae 



Three genera and four species of Brissidae, Brissus, 

 Metalia, and Rht^nobhssus are found at Enewetak. Three of 

 the species have been reported previously from the atoll. 

 A. H. Clark (1952, 1954) recorded Brissus latscarinatus 

 from Enewetak and from elsewhere in the Marshall Islands. 

 Rhi;nobrissus hemiasteroides is recorded by Pomeroy and 

 Kuenzler (1967), and Metalia spatagus is newly recorded 

 from Enewetak and the Marshall Islands. 



Clypcasteridae 



Cliipeaster reticulatus, the only representative of the 

 Clypeasteridae known from the Marshall Islands: (A. H. 

 Clark, 1952, Bikini; 1954, Taka and Ujac) is newly 

 recorded from Enewetak. 



Laganidae 



The family Laganidae is represented by Lagonum 

 depressum at Enewetak and other Marshall Islands (A. H. 

 Clark, 1952, 1954). 



COLLECTION RECORDS 



Ophlomyxidae 



Neoplax crassipes 



Enewetak Islet: July 16, 1960, shallow coral head, J. H. 



