PART 1 GARTH : PACIFIC OXYRHYNCHA 407 



times absent. Two large branchial spines, the hinder one in a transverse 

 line with the anterior cardiac spine and with the spine at the postero- 

 lateral angle ; a smaller, epibranchial spine ; one or two small branchial 

 spines opposite the interval between the two cardiac spines ; a spine either 

 side of the anterior gastric spine ; one or two pairs of small spines between 

 the orbits. A small subbranchial spine invisible from above and a few 

 pterygostomian spines. Rostral horns short, triangular, outer margins 

 slightly converging. [Orbital spines short, orbital opening narrow.] 

 Basal antennal article with two anterior spines ; a spine near outer angle 

 of buccal cavity. 



Four spines and a few tubercles on upper margin of merus of cheli- 

 ped ; at subequal distances three other rows of tubercles. (Rathbun, 1925, 

 of Stenocionops macdonaldi, revised to omit comparative references to 

 S. spinimana) 



Young: Carapace triangular-ovate, broadened behind. Median spines 

 nine, distributed as in the adult, none on the posterior margin; spines 

 unequal, the largest the anterior cardiac, the two posterior, and the 

 penultimate gastric. Lateral marginal spines three, large, one hepatic 

 (hepatic region not enlarged), two branchial, with the spine at the 

 posterolateral angle the largest and pointing obliquely backward. Two 

 large spines on the elevated portion of the branchial region ; a low spine 

 in front of each; a spine on either side of the anterior median spine. 

 Rostral horns widely divergent, at nearly a right angle, regularly taper- 

 ing to slender tips. Orbital spines narrow. (Rathbun, 1925, of Steno- 

 cionops triangulata) 



Material examined: 10 specimens from 9 stations. (See Table 85) 

 From Tiburon Island, Gulf of California, Mexico, to Santa Elena Bay, 

 Ecuador. In addition to the above, 8 specimens from 6 Galapagos stations. 

 (Garth, 1946, of Stenocionops triangulata) 



Color in life: Pink with olive brown pubescence. Chelae dark brown. 

 (Crane, of Stenocionops macdonaldi from the Gulf of California) 



Habitat: Coral sand. (Bell) Green, brown, and yellow mud; fine 

 gray and yellow sand; broken shell and sponge. (Rathbun) Coarse shelly 

 sand with weed. (Crane) Velero III specimens were taken three times 

 on sand and shell bottom, twice on sandy mud or mud bottom, once on 

 rocky bottom, and once on coralline bottom. 



Depth: 8 to 55 fathoms; in the Galapagos to 150 fathoms; in the 

 Gulf of California to 145 fathoms. (Rathbun) 



