ent in North America (Rathbun, 1935). Toula 

 (1911) considered the Miocene form from Panama 

 to be conspecific with the living species in the 

 West Indies region, but Rathbun (1918a) con- 

 sidered this form as distinct (P. bouvieri) and 

 possibly ancestral to the modern species. 



Petrochirus diogenes is the largest hermit crab 

 in the Carolinian fauna and this feature, plus its 

 coarsely tuberculate, ruddy appendages, makes it 

 conspicuous. A common commensal is the porcel- 

 lanid crab, Porcellana sayana, and other com- 

 mensals on the shells carried by the crab, such as 

 Crepidula plana (Say), bryozoans (Scrupocel- 

 laria sp.), tubicolous worms (Hydroides sp. and 

 Spirorbis sp.) and other species, are mentioned by 

 Pearse (1932b). Ovigerous females have been re- 

 ported in March from the Virgin Islands (Pro- 

 venzano, 1961). 



Pearse (1932a) determined the freezing point 

 of P. diogenes blood (range -1.90° to -2.32° C). 



Holthuis (1959) reviewed the complex nomen- 

 clatural history of the species, designated the type, 

 restricted the type locality, and delimited the 

 geographic range. 



Genus Dardanus Paulson, 1875 



Paulson, 1875, t>. 96 (translation). — Hemming, 

 163. — Provenzano, 1959, p. 372. 



1958b, p. 



KEY TO SPECIES IN THE CAROLINAS 



a. Propodus of second left walking leg conspicuously 

 hairy, with a lateral longitudinal ridge paralleled by a 

 groove, ridge crossed by rugae venosus (p. 123). 



aa. Propodus of second left walking leg not hairy, with- 

 out a lateral longitudinal ridge or groove, rugae ar- 

 ranged in herringbone pattern insignia (p. 124). 



Dardanus venosus (H. Milne Edwards) 



Figure 99 



Pagurus venosus H. Milne Edwards, 1848, p. 61. 

 Dardanus venosus: Verrill, 1908, p. 441, text-figs. 58-59 ; pi. 

 26, figs. 4a, 5a. — Provenzano, 1959, p. 374, fig. 6 (rev.). 



Recognition characters. — Anterior shield of 

 carapace slightly longer than width of front, 

 smooth, with few hairs and some deep lines near 

 sides; anterior margin with rostrum wanting, 

 lateral projections between bases of eyestalks and 

 antennae prominent. Eyestalks stout, slightly 

 constricted in middle, extending to tips of an- 

 tennal peduncles or slightly beyond, a tuft of 

 setae just behind cornea; eye scales widely sepa- 

 rated, inner margins straight, blunt tips bearing 



Fioube 99. — Dardanus venosus (H. Milne Edwards). A. 

 anterior part of body in dorsal view showing ridge on 

 second left walking leg ; B, inner surface of major 

 chela showing "veins" which specific name describes ; 

 A-B approximately X 1.5 (after Provenzano, 1959). 



several spines. Antennular peduncles exceeding 

 cornea by one-third of terminal peduncular ar- 

 ticle. Acicles short, reaching midlength of eye- 

 stalks, armed with small, sharp spines. 



Chelipeds unequal, left much larger than right; 

 fingertips black, corneous, spooned. Major chela 

 with outer surface covered by scalelike tubercles 

 separated by fan-shaped fringes of appressed 

 hairs, inner surface smooth, medial margin bear- 

 ing row of seven sharp, horny-tipped spines con- 

 tinued as row of smaller spines on dactyl and as 

 well-developed spines on carpus; carpus with 

 smaller sharp spines scattered over surface. Minor 

 chela narrower, lacking scalelike tubercles on 

 outer surface, and with long setae rather than 

 appressed bristles. Walking legs with dactyls 



MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 



12' 



