1917 Way; on Ta.ronomi/ of Crabs 371 



Abundant everywhere in the region in eel grass (Zostera marina), on 

 kelp, and on piles under docks ; common to at least 40 fathoms. 



Genus Scyra 

 1. Scyra acutifrons Dana. sharp-nosed crab (fig. 27) 



Rostrum bifid ; horns short, broad, leaf-like, tapering to points that 

 diverge. Antennae short, not much longer than the rostrum. Supraorbital 

 spine small, inconspicuous. Carapace pyriform, with very irregular sur- 

 face ; a conspicuous H-shaped depression breaks up the surface into several 

 prominent elevations, producing a small acute anterior tubercle in the 

 median region and a larger, more rounded one just posterior to it; branchial 

 regions tumid with large rounded tubercles, anterior to them are eleva- 

 tions which may bear small tubercles ; another large blunt tubercle near 

 the posterior margin in the median line. Chelipeds much larger in male 

 than in female; merus elongated, rounded above, flattened on lower side, 

 surface very much roughened with prominent tubercles ; carpus rough, 

 more or less reticulate with tubercles; hands elongated, very acute on 

 upper surface, particularly in old males; middle portions of hand more 

 or less inflated, surface granulated ; fingers deflexed, toothed on inner 

 edge, in old males gaping considerably at the base. Walking legs more or 

 less subcylindrical, quite pubescent ; dactyls with sharp corneous tips much 

 shorter than propodi. Great variations occur in surface of the carapace 

 due to the age ; tubercles are usually smoother in females and rougher 

 and more prominent in old males. Color dull, usually gray or tan with 

 more or less red on chelipeds and walking legs, usually body so encrusted 

 with bryozoans that it is difficult to see the color. Like other spider crabs, 

 they are usually covered with a variety of decorative materials. Sponges, 

 hydroids, and bryozoans are used b}' them more than algae. 



Miss Rathbun reports them to range from low tide to iO fathoms, 

 but none was found near the tide lines anywhere in the vicinity. They 

 were found ofi" the northeast and east side of Brown Island (8) in 20 to- 

 55 fathoms. On July 7, 1916, 2 females were taken with eggs. Not 

 particularly abundant. 



Genus Hyas 

 1. Hyas lyratus Dana. lyre crab (fig. 26) 



Rostrum bifid ; liorns broad at base, tapering to points that curve 

 inward, forming hooks at the ends. Antennae short, not extending far 

 beyond the rostrum, the 2 basal joints constituting one-half their length; 

 with 2 calcareous knobs on the ventral surface just below and at the side 

 of tlie base. Carapace with leaf-like expansion formed by union of 2 

 anterior lateral spines posterior to the eye; leaf-like expansion with outer 



