Boone, Crustacea, Cruises of " Eagle'' and "Ara," 1921-28 105 



Geniis : MACEOCOELOMA Miers. 

 Macrocoeloma eutheca Stimpson. 



Plate 32, fig. B. 



Name : Tube-eyed sponge crab. Orange sponge crab. 



Diagnostic characters: Eostral sinus U-sbaped. Orbital tubes 

 very long. Carapace subpyriform, decidedly constricted behind orbits. 



Type : The localities of Prof. Stimpson 's type specimens are given 

 as "off French Reef, 15 fms., and west of Tortugas, 37 fms." The 

 types, unfortunately, are not extant. 



Distribution : Although this species was established in 1781, only 

 about twenty specimens have been recorded since. These come from 

 Miami, Florida, southward through the Florida Keys, the Bahama 

 Banks, Barbados, off Havana, Cuba, St. Croix, near Colon, Panama, 

 and off Yucatan. 



Material examined : One female, dredged in 20 fms., off Sand Key 

 Light, Key West, Florida, January 29, 1924. 



Color : This exquisite little crab is a vivid orange flame color, with 

 golden brown eyes. The surface of the carapace and appendages are cov- 

 ered with hooked hairs, by means of which the crab fastens bits of 

 seaweed, or more frequently sponges, to itself as a camouflage. This 

 quaint procedure enables the grotesquely humped little creature to 

 become as indistinguishable a fragment of its environment as is one 

 of the tiny blocks in an age-mellowed Florentian mosaic. 



When one recalls that Macrocoeloma eutheca is an inhabitant of the 

 coral rock bottoms of shallow waters, ranging occasionally down as 

 deep as 45 fathoms, the seemingly grotesque form with its corruga- 

 tions and rugosities is recognized as a marvelously perfect replica 

 of a bit of that eons-old geologic formation so well known to all 

 students of the West Indies. 



Seen only in the dredge net, one marvels that such perfection of 

 sculptured mimicry should apparently be counteracted by the flaming 

 orange color — a hue reminiscent of the vivid butterfly-weed of Vir- 

 ginian meadows. Yet I have spent hours searching for this species 

 off the Cocolobo Cay, dawn-to-sunrise hours, a period of maximum 

 activity for this little creature, whose uncanny gift of camouflage 

 defied penetration. The flaming orange hue, semi-clothed by sponges. 



