364 HAWAIIAN AND OTHER PACIFIC ECHINI. 



labelled. Original specimens in the M. C. Z. collection from "Hilo. W. Stimp- 

 son" and "N. E. end of Niphon. W. Stimpson" are indistinguishable. This 

 view is confirmed by the fact that the "Albatross" failed to collect any Strongy- 

 locentrotus in the Hawaiian Islands. 



The pedicellarise of this species show some interesting features. The globif- 

 erous are not rare in very young specimens but are less common in those half 

 grown and are almost entirely wanting in adults. The reverse of this is true 

 of the tridentates, which are very common in adults and occur in two or three 

 different forms, but are less common in half grown specimens, and are rare in very 

 young individuals. The globiferous appear to be of two different sizes, one 

 with valves .30 mm. long and the other with valves about .80 mm. (PI. 94, figs. 

 18, 19). It is possible these forms intergrade but intermediate sizes do not 

 occur in the M. C. Z. material. The tridentate occur in such a variety of forms 

 that it is not easy to group them exactly, but three rather distinct kinds may be 

 recognized. In one of these the valves (PI. 94, fig. 21) are from .20 to .50mm. 

 in length, rather wide and flat, bluntly rounded and in contact for most of their 

 length; in a second, the valves (PI. 94, figs. 22, 23) are very long (1.5-2 mm.) 

 and narrow and in contact only for more or less of their distal half; in the third, 

 the valves are about 1.5 mm. long, with broad, curved blades in contact at their 

 tips. The ophicephalous occur in two forms, one with valves .20 mm. besides 

 the loop and the other about .50 mm. also besides the loop; the valves are notice- 

 ably constricted. The triphyllous (PI. 94, fig. 20) are neither rare nor peculiar. 

 The spicules are not common; they are curved rods, branched at the ends. 



The specimens taken by the "Albatross" range from 23 to 75 mm. in diameter. 

 The smallest is dull purplish with an evident greenish tinge abactinally, while 

 the spines are more or less greenish. There are six pairs of pores in each arc 

 in the mid-zone but the uppermost arcs contain seven as a rule. In the larger 

 specimens, the color is uniformly dark reddish brown with no trace of green. In 

 the largest specimen, there are six pairs of pores in each arc at the ambitus, 

 but just above, there are a few arcs with seven; then follow a few with six and 

 the uppermost have only five, indicating a senescent change. 



The "Albatross" collected this species at the following stations: 



Station 4807. Between Hakodate and Sado Island, Japan, 41 36' 12" N., 

 140 36' E. Bott. temp. ? 44-47 fathoms. Sh., crs. g. 



Station 5018. Off Cape Tonin, Saghalin Island, Japan, 46 41' 30" N., 

 143 57' 40" E. Bott. temp 30.4. 100 fathoms. Br. m., bk. s., p. 

 Hakodate. 

 Seven specimens. 



