28 Bulletin, Yanderhilt Marine Museum, Vol. Ill 



Genus: CALCINUS Dana. 

 Calcinus explorator Booue. 



Plate 3. 



Diagnostic characters: Propodus and dactyli of great cheliped 

 almost subeircular, palm wider distally than its length in the median 

 line; meral and carpal joints of the second and third right ambu- 

 latories equal to or only a little longer than those of the left legs. 



Type: The type, an adult male specimen, was taken at "Ardurus" 

 Station 54, Hood Island, Galapagos, in 15 fms., by Dr. William Beebe, 

 while diving, and is deposited, together with forty-odd additional 

 specimens, in the collections of the Tropical Research Station, New 

 York Zoological Society. 



Distribution : Restricted to the Galapagos ; littoral. 



Material examined: One specimen taken by the ^'Ara" in tide- 

 pool, Eden Island, near Indefatigable Island, Galapagos, March 12, 

 1928, Four, Hood Island, Galapagos, in shells of Cerithium macu- 

 losum K., February 5, 1928. 



Color : See type description. 



Technical description : Carapace with the frontal margin almost 

 straight; rostral point very small, lateral projections even more ob- 

 scure. Precervical region of carapace with hard dorsal plate squarish, 

 having margins subparallel, except posteriorly, where they converge 

 slightly, forming a rounded posterior margin. Lateral walls and 

 posterior region subglobose — membranous. 



Ocular peduncles about as long as the anterior border of the cara- 

 pace, cornea terminal, hemispherical, ocular scale about as long as the 

 inner side of the basal antennal joint, sublobate, tapering to an acute 

 point, separated from each other by a V-shaped space. 



Outer antennae with basal joint about two-thirds as broad as ocular 

 peduncle and having the outer dorsal distal angle produced acutely 

 and finely serrate on the margin of the produced joint; the second 

 joint is small, ventrally placed, triangulate; the third joint is com- 

 pressed, cylindrical, almost concealed dorsally by the acicule, which 

 arises from the first peduncular segment, tapering conically to an 

 apex, being about as long as the third peduncular article and having 

 the inner dorsal margin quadriserrate. The fourth peduncular article 

 is about as long as the dorsal view of the first three articles taken to- 

 gether, slenderer, cylindrical, somewhat flattened dorsoventrally and 



