Boone, Crustacea, Cruises of "Eagle" and "Ara," 1921-28 103 



Although this crab has been known to naturalists since 1750, its 

 coloration and habits are still a matter of conjecture. 



Habits : This appears to have been one of the first spider crabs to 

 have its curious habit of dressing itself in bits of sponge, seaweed, 

 etc., recorded. One glance at the many stiff-hooked hairs on the body 

 and feet of the crab will suffice to show how well equipped this crea- 

 ture is to fasten its living ' ' clothes ' ' to its body. These safety-pin-like 

 hairs are assisted in their function by the fact that the crab also 

 secrets a cement-like substance from a gland in its mouth, which is 

 used to glue the bits of seaweed, etc., onto its body, thus effecting a 

 camouflage alike from would-be devouring enemies and from its prey. 



Color : Mr. Vanderbilt 's field-sketch, made from a specimen dredged 

 in 30 fathoms, 14 miles southwest of Marquesas Keys, Florida, appears 

 to be the first record of the color of this crab, which has been known 

 to science since 1750. The body is dark vinaceous red, the legs are 

 lighter red. This coloration imitates that of one of the well known 

 West Indian sponges. 



Technical description : The entire upper surface of the body and 

 legs is covered with a dense coating of red felt, composed of long, 

 pointed vesicles, among which are interspersed many large, curved, or 

 hooked hairs. Carapace elongate pyriform, upper surface rendered 

 moderately uneven by the series of elevations. Rostral horns, two 

 long, equal in length to from one-third to one-half the length of the 

 carapace; slender, pointed, sharply divergent at base, but sometimes 

 with the tips incurved, or subparallel. Superior preorbital spine very 

 prominent, acute, projecting above the eye, hood-like; superior post- 

 orbital spine also acute, but much smaller than the preorbital spine 

 from which it is separated by a linear sinus. The lateral margin of 

 the carapace is armed with four large, acute spines, one hepatic and 

 three branchial in position. The dorsum has a rounded prominence 

 on the cardiac and gastric regions each ; two projections on the intes- 

 tinal region, the anterior of which is quite rudimentary, but the pos- 

 terior one is produced into a curved spine which projects over the 

 posterior margin. 



The antennulae fold almost vertically within the septum. 



The antennae have the basal joints enlarged, anchylosed, the antero- 

 intemal angle produced into an acute spine, the antero-external angle 

 produced into another acute spine, which is subequal to the post- 

 orbital spine; the flagellum is a long, slender, two- jointed rod, curi- 



