78 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loi 



rence in other areas are still too scattered and frequently too unreli- 

 able to justify the usual distribution note that Planes is "found in all 

 tropical and temperate seas." 



8 9 10 12 6 20 25 



Carapace Length (mm.) 



Figure 7. — Relative growth of the three terminal segments of the second walking leg in 

 Planes minutus, Planes cyaneus, and Pachygrapsus marinus, based on mean values (table 

 3) plotted logarithmically. 



The more reliable locality records for the species of Planes are 

 indicated in figure 8. Not included on this chart are several references 

 in the literature to Australian specimens without specific locality 

 data. Even some of the localities indicated, particularly those from 

 older records, require verification. It is obvious that in some cases 

 specimens picked up at sea have been referred to the last port of call 

 of the vessel involved. The large lot of specimens recorded by Dr. 

 Rathbun (1918, p. 257) from the Galapagos Islands (U.S.N.M. No. 

 5046) prove to belong to the Atlantic Planes minutus. This deter- 

 mination is substantiated by the fact that the shrimp from the same 

 collection belong to the Sargassum fauna of the North Atlantic. 

 Similar circumstances may explain the record of the single specimen 

 of P. cyaneus from Mauritius (U.S.N.M. No. 17667) if the presence 

 of P. minutus alone in the Indian Ocean is borne out by other material. 

 Even one of the lots of P. minutus from that region, that from Kergue- 

 len Island (U.S.N.M. No. 15054), is questionable; in the collections of 



