PART 1 GARTH I PACIFIC OXYRHYNCHA 363 



Mithrax (Mithrax) sinensis clarionensis Garth 

 Plate V, Fig. 6 ; Plate 41, Fig. 3 

 Mithrax (Mithrax) clarionensis Garth, 1940, p. 63, pi. 15, figs. 1-3. 



Type: Female holotype, U.S.N.M. No. 78777, length 12.9 mm, 

 width 12.5 mm. 



Type locality: Sulphur Bay, Clarion Island, Mexico, 57 fathoms; 

 Velero III station 137-34. 



Diagnosis: Areoles of carapace finely tuberculate. Anterolateral 

 prominences sharply compound-tuberculate. Base of hand paved with 

 rounded granules. Otherwise as in the parent species. 



Description: Differing from typical Mithrax (Mithrax) sinensis 

 in the following particulars: Carapace paved with much finer tubercles 

 and granules, there being approximately twice as many raised promi- 

 nences on any area chosen for close examination^ as, for example, the 

 gastric shield. Protuberances of anterolateral margin, excepting the last, 

 subdivided into as many as five spines each, the last single. Largest of 

 basal antennal spines acute and incurving. Manus of cheliped with flat- 

 tened granules proximally. Of the other distinctions mentioned in the 

 original description, the greater breadth of the carapace a character asso- 

 ciated with the female sex, and the third interorbital spine absent in about 

 half of the specimens, especially in the young. 



Material examined: 14 specimens from 4 stations, all Clarion Island, 

 Mexico. (See Table 74) 



Measurements: Male: length 10.4 mm, width including spines 10.3 

 mm, without spines 10.0 mm, rostrum 0.7 mm, width 2.1 mm, cheliped 

 16 mm, chela 8.0 mm, dactyl 3.4 mm, height of palm 2.8 mm, ambula- 

 tory legs 15.5, 14, 12.5, and 9 mm, respectively. Female holotype: length 

 12.9 mm, width including spines 12.9 mm, without spines 12.5 mm. 

 Color in life: See Garth (1940, p. 64). 

 Habitat: Sand, coral, and nullipore bottom. .. 

 . Depth. 15-57 fathoms. 

 Size and sex: -Males in the series are from 6.2 to 10.4 mm, females 

 from 5.7 to 12.9 mm, ovigerous females from 5.8 to 10.0 mm. The small 

 size of the breeding females, 5.8 and 7.5 mm, should be noted in com- 

 parison to the breeding range of the mainland form, as it presents another 

 racial characteristic. 



Breeding: The three ovigerous female paratypes were obtained by 

 the' Velero III in March. 



