20 



PROCEEDINGS OF THE NATIONAL MUSEUM 



infracorneal tooth. From A. haswelli Coutiere, 1908, by the shorter 

 carpus of the first legs in the female. From A. japonicus Kubo, 1936, 

 by the slightly shorter rostrum, the absence of a dorsal carina behind 

 the rostrum, smaller infracorneal tooth, longer stylocerite, shorter 

 outer spine on the antennal scale, and more robust appendages. 

 From A. lamellifer Kubo, 1940, by its much shorter rostrum and 

 shorter and stouter appendages. From A. minikoensis Coutiere, 

 1903, by the blunt, rather than sharp, infracorneal tooth and by the 

 carpus of the first leg in the female being more than one-half as long 

 as the merus; the specimens assigned to this species by de Man 

 (1911b, p. 149) have the infraorbital tooth blunt as in A. marshallen- 

 sis, but the telson is 3.8 rather than 2.7 times as long as the width of 

 its posterior margin and the stylocerite is slightly shorter than in 



Table 2. — Length to width proportions of the leg segments in females 

 of Athanas marshallensis (^italics) and A. stebbingii. 



Right first leg 

 Left first leg.. 



Third leg 



Fourth leg 



Fifth leg 



Merus 



4.3 5. 9 



4.3 6. 1 



3.8 5. 2 



3.9 4. 8 

 3.8 4. 8 



Carpus 



3. 2 

 3.0 



4.0 



5.0 

 5.5 

 4.2 

 3.6 

 3.8 



Propodus 



6.6 

 6.7 

 6.4 



9.3 



8.7 

 8.7 



A. marshallensis. From A. orientalis Pearson, 1905, b}^ the slightly 

 shorter rostrum and shorter extracorneal and, especially, infra- 

 corneal teeth. From A. ohsimai Yokoya, 1936, by the longer anten- 

 nal scale, less massive movable finger of the first cheliped in the 

 male, and shorter fingers of the first cheliped in the female. From 

 A. polymorphus Kemp, 1915, by the absence of a pterygostomian 

 tooth and more robust appendages. From A. ienuipes de Man, 1910, 

 by the more robust appendages and much broader telson. A. mar- 

 shallensis appears to be most closely allied to A. stebbingii de Man, 

 1920, described from a single ovigerous female from the Java Sea, 

 but it differs from the description and figures of that species (de Man, 

 1922, p. 18, pi. 2, figs. 10-lOa, pi. 3, figs. lOb-f) by its somewhat 

 broader telson and stouter appendages; the telson in A. marshallensis 

 is 1.5 times as long as its basal \vidth and 2.7 times as long as its 

 distal width, while the corresponding figures for A. stebbingii are 1.7 

 and 3.4 mm., respectively; the above table shows the proportions 

 of the leg segments in A. marshallensis compared with those computed 

 from de Man's measurements of the type of A. stebbingii. 



