151 
The radioles are long, ca. 1 Va h. d., siender, slightly tapering. 
They are provided with finely serrated ribs, and the surface other- 
wise covered with short, simple hairs. The oral radioles (Fig. 4) 
are fairly distinctly serrated along the edges and may be slightly 
curved; when worn, the serrations may be quite obsolete. The 
secondary spines are fairly long, those round the radioles are flat- 
tened, the rest of them more or less distinctly cvlindrical. 
Only globiferous pedicellariæ are found (on the specimens in 
hånd, at least). The larger ones (PI. VIII, Fig. 1) have fairly elong- 
ate, narrow valves, with a very irregular, thorny meshwork on the 
inner side, below the opening. There is no endtooth. The stalk is 
simple, without a limb. The smaller forms (PI. VII, Fig. 2) have a 
rather distinet endtooth. Possibly the larger forms, found in the 
material available, do not in reality represent the large globiferous 
pedicellariæ; this cannot be decided at present. But, at any rate, 
there are all transitions between the two forms figured. — Spicules 
of the tubefeet of the usual type. 
Colour of the test slightly greenish on the aboral side; the 
radioles with a faint pinkish tint, mainly in their basal part. 
The large genital pores indicate that this species has large eggs 
and probably protects its brood. 
It seems fairly evident that this form is related to the genus 
Austrocidaris , with which it agrees in the characters of the sunken 
median area of the ambulacra and interambulacra. Also the struct- 
ure of the pores and the radioles is the same. On the other hånd 
it differs so markedly from that genus in the exsert oculars and 
the covering of the peristome, as also in the structure of the pedi¬ 
cellariæ, that it seems unjustifiable simply to refer it to that genus. 
The character of the peristome recalls the genus Aporocidaris, but 
the apical system is not of the character peculiar to that genus, 
and also the pedicellariæ are different. I do not see any other 
possibility than to establish a separate genus for it, the diagnosis 
of which is as follows: 
Ogmocidaris ! ) n. g. Test low, height only half h. d. Interam- 
bulacral plates 6—7; areoles rather deep. A sharply limited, naked, 
1 o y/iog = furrow. 
