PHYMOSOMATIDjE. 227 



briefly described by Doderlein (1906, Zool. Anz., XXX, p. 520), who proposes to 

 place the genus in Mortensen's family Toxopneustidaa, because the valves of the 

 globiferous pedicellariae terminate in a single prominent tooth. It is interesting 

 to note that the first protest against this classification is made by Mortensen 

 himself (1910, Vid. Med., p. 31), who considers the pedicellarise an unsafe guide 

 in this case. 



The globiferous pedicellarise (PL 92, fig. 1) are remarkable for their stalks, 

 which have 3-5 branches on each side. These pedicellarise are well distributed 

 and fairly common. The valves (figs. 6, 7) are of very variable size, ranging 

 from .25 to .75 mm. in length, while the single terminal tooth is from one fourth 

 to one third as long. These pedicellariae are quite unlike anything found in the 

 Arbaciadse and resemble only in a general way certain forms occurring in the 

 Echinidse. 



The tridentate pedicellarise (PL 92, fig. 2) are rather uncommon and in one 

 of the two specimens examined appear to be wanting. They usually have a 

 neck, which may be quite long, but in some cases appears to be wanting. The 

 valves (PL 92, fig. 5) are broad and in contact only along the distal half. They 

 are 1-1.60 mm. in length and the margin is either entire or finely sinuate. 



The ophicephalous pedicellarise (PL 92, fig. 3) are very common, particularly 

 actinally. The valves (PL 92, fig. 9) are short and wide, somewhat rounded 

 triangular in outline, with a low wide "loop" which is essentially the same on 

 each valve. The apophysis is prominent and continuous with the coarse mesh- 

 work which occupies the centre of the blade. The margin is slightly sinuous at 

 least near the tip. The valves measure about .75 mm. in length and are nearly 

 two thirds as wide. 



The triphijllous pedicellarise (PL 92, fig. 4) are small and not very abundant. 

 The valves (PL 92, fig. 8) are rather elongated and rounded at the end. They 

 measure about .25 mm. in length and are a little more than half as broad. 



The sphceridia (PL 92, fig. 10) of Glyptocidaris are numerous, as many as 

 15-20 occurring on each side of each ambulacrum. They are not sunken in pits 

 but are borne on the surface of the upper demi-plate, of each ambulacral plate, 

 from the actinostome to some distance above the ambitus. They are nearly 

 spherical and are situated at the inner end of the demi-plate, beside the tube-foot. 



The spicules (PL 92, fig. 11) in the tube-feet are in the form of rods, expanded 

 and perforated at the middle but more or less drawn out at each end. 



