6 PROCEEDESTGS OF THE NATIONAL MUSEUM vol. 105 



Kigili Island; surface light at night; May 24, 1946; L. P. Schultz; 

 10 males, 28 females and juveniles. — Lagoon; subtidal; June 6, 1946; 

 M. W. Johnson; 1 female. 



Rongelap Atoll: Lagoon one-half mile off Yugui Island; 13 fathoms; 

 surface light at night; July 30, 1946; E. S. Herald; 33 males, 101 

 females and juveniles. — Lagoon one-half mile off Lomuilal Island; 13 

 fathoms; surface light at night; July 31, 1946; E. S. Herald; 2 males, 

 3 females. 



Rongerik Atoll: Lagoon 200 yards off Eniwetak Island; surface 

 light at night; June 28, 1946; L. P. Schultz and E. S. Herald; 12 males, 

 5 females. 



This is by far the commonest decapod crustacean in the collections 

 made during the Marshall Islands surveys. The fact that it was 

 taken at a surface light in great numbers at some times and sparsely 

 or not at all at other times may or may not indicate that a lunar 

 periodicity of some sort is involved. 



More or less critical examination of more than 500 specimens in 

 the present collections indicates that but one species is involved. 

 Of this number, only two specimens can be considered aberrant. 

 One has three instead of two pairs of telson spines anterior to the 

 terminal ones; the other specimen has two lateral spines on one side 

 of the telson and only one on the other side. The collections would 

 indicate, therefore, that the genus is represented by but a single 

 species in the Marshalls area, whereas Armstrong (1941) found two 

 {L. robusta and L. aculeocaudata hainanensis) in a collection from 

 Samoa. It may be of interest that the specimens recorded from the 

 Hawaiian Islands by Rathbun (1906, p. 929) are, as her description 

 indicates, not L. robusta; they appear to belong to a species closely 

 allied to, and possibly identical with, L. aculeocaudata Paulson. 

 Considerable additional study of the Indo-Pacific species of Leptochela 

 must be made before the various forms can be defined satisfactorily. 



The dentition of the fingers of the second chela in 100 specimens 

 selected at random from the lot taken in Bikini lagoon shows greater 

 variation than has been evidenced heretofore (table 1). In general, 

 the number of spines on the fingers appears to increase with the size of 

 the specimen. The largest specimen critically examined, a female with 

 a carapace length of 3.7 mm., has 54 spines on the fixed finger, whereas 

 the smallest specimens have but 28 to 34 spines. Although the modal 

 numbers of these teeth probably are of specific importance, especially 

 when correlated with specimen size, it is apparent that the number is 

 less sharply defined for each species than Kemp's diagnoses would 

 indicate. The number of small spines in the intervals between the 

 larger ones at the middle of the fingers may be of greater taxonomic 

 importance, but here also there is considerable variation; in the speci- 



