REPORT ON THE ECHINOIDEA—MORTENSEN 25 
ambulacral spines are constricted in their distal part, being thus 
somewhat pointed and also somewhat longer than usual. Genital 
pores have not yet appeared, whereas in typical hastigera they are 
already fully developed at a size of 8 mm. horizontal diameter, which 
fact would tend to indicate that it reaches a larger size than the 
typical hastigera. The tridentate (and quadridentate) pedicellariae 
are different from those of typical hastigera, broader and more like 
those of profundi. Quadridentate pedicellariae have not been 
observed in hastigera. In the characters of the test and of the spines 
it otherwise resembles hastigera, and also the color is the same—a light 
purplish on the test and secondary spines, the primary spines as well 
as the denuded test being white. 
I rather think that this form will ultimately prove to represent a 
distinct species. But with only one specimen at hand one cannot 
determine how constant the characters pointed out are, so it would 
seem the better course for the present to designate it simply as a 
variety of hastigera, to which species it is, at any rate, closely related. 
To identify it merely as hastigera I do not think justifiable. 
Family ARBACIIDAE 
Genus PYGMAEOCIDARIS Doderlein 
PYGMAEOCIDARIS PRIONIGERA (A. Agassiz) 
Podocidaris prionigera A. AGAssiz, Challenger Reports, Zoology, vol. 3, pt. 9, 
Echinoidea, p. 59, pl. 34, figs. 14, 15, 1881. 
Pygmaeocidaris prionigera DODERLEIN, Wiss. Ergebn. Tiefsee-Exped., vol. 5, Lief. 
2, p. 185, pl. 22, fig. 2; pl. 29, fig. 6; pl. 35, fig. 4; pl. 45, fig. 5, 1906—KorHLrr, 
Investigator Echinoidea, pt. 3, p. 68, pl. 11, figs. 7-9, 1927—MorTEensen, Mono- 
graph of the Hchinoidea, vol. 2, p. 553, pl. 87, figs. 27-35, 1935. 
Locality —Station 5608; Gulf of Tomini, Celebes; Binang Unang 
Island (peak) bearing S. 87° E., 19 miles distant (lat. 0°08’00” S., 
long. 121°19’00’’ E.); 1,991 meters; bottom temperature 2.39° C.; 
gray mud; November 18, 1909. One specimen. 
Remarks.—This specimen, 13 mm. in diameter, is a good deal larger 
than the other four specimens hitherto known, the largest of which 
was only 9.5 mm. in diameter. 
Though not in the very best condition—the spines are nearly all 
broken—this specimen has afforded a very welcome opportunity for 
adding to our knowledge of this highly interesting rare deep-sea 
echinoid. 
Curiously, the contents of the intestine were found to be only bits 
of land plants, which must have been washed out from the shore and 
sunk to the bottom to form the vegetarian diet of this small deep-sea 
echinoid as well as of so many of the echinothurids. 
