STRONGYLOCENTROTUS FRAGILIS. 355 



arcs themselves approach the horizontal at ambitus, yet the poriferous areas 

 and the ambulacra are rather narrow. The actinostome is more or less deeply 

 sunken and measures about .30 h. d. in diameter. The actinostomal membrane 

 is almost wholly free from calcareous plates, excepting the ten that make up the 

 buccal ring. The abactinal system is about .20 h. d. across. Oculars I and V 

 are broadly insert in 55-60% of the specimens, but in a number, V is exsert and 

 in several none of the oculars reach the periproct. The primary spines are 15- 

 20 mm. long and are exceedingly slender and brittle, as are the secondaries and 

 miliaries. The color of the test ranges from orange-red to deep purple, but the 

 spines are less varied, orange-red at base becoming yellowish or whitish at tip. 

 The pedicellariae (PL 94, fig. 28, 29), sphajridia, and spicules do not appear to be 

 in any way different from those of drobachiensis. 



The "Albatross" took this species at the following stations off the west coast 

 of the United States and Canada : 



Station 2839. Off Santa Barbara Islands, California, 33 8' N., 118 40' W. 

 Bott. temp. 41.4. 414 fathoms. Gy. s. 



Station 2861. North of Vancouver Island, 51 14' N., 129 50' W. Bott. 

 temp. 42.6. 204 fathoms. There is some doubt as to whether the specimens 

 really came from this station. 



Station 2886. Off Oregon, 43 59' N., 124 56' 30" W. Bott. temp. 48.1. 

 50 fathoms. Rky. 



Station 2890. Off Oregon, 43 46' N., 124 57' W. Bott. temp. 42.2. 

 277 fathoms. Gy. s. 



Station 2896. Off southern California, 33 55' 30" N., 120 28' W. Bott. 

 temp. 42.8. 376 fathoms. Yl. m. 



Station 2925. Off southern California, 32 32' 30" N., 117 24' W. Bott. 

 temp. 42.9. 339 fathoms. M. 



Station 2927. Off southern California, 32 43' N., 117 51' W. Bott. temp. 

 43.3. 313 fathoms. Gn. m. 



Station 2928. Off southern California, 32 47' 30" N., 118 10' W. Bott. 

 temp. 41. 417 fathoms. Bk. s., g. 



Station 2935. Off southern California, 32 44' 30" N., 117 23' W. Bott. 

 temp. 49.2. 124 fathoms. Fne. gy. s. 



Station 2936. Off southern California, 32 49' N., 117 27' 30" W. Bott. 

 temp. 49. 359 fathoms. M. 



Station 2946. Off southern California, 33 58' N., 119 30' 45" W. Bott. 

 temp. 56.5. 150 fathoms. Crs. gy. s. 



