OF NEW SOUTH WALES. 163 



without cuts ; porif. zones broad, pores in well-defined vertical 

 rows or short arcs of three pairs. A. space broad, tubercles of 

 both areas, small and uniform in size ; median spaces frequently 

 bare. Spines few, slender, far apart. Sutural pores at angles of 

 plates ; auricles tall, slender, scarcely meeting above large 

 foramen, with high connecting ridges. 



Ambltpneustes ovum. Lamk. 



The common globular urchin of all the southern coasts where 

 it is often found in immense numbers, drifted up by the tide on 

 sandy beaches. It is not at all common on the east coast of 

 Australia. As there are other species very closely resembling it, 

 I must define them, for they are nearly always confused in 

 collections. The general color of the test is light olive, but very 

 variable in the depth of shade ; in fact, I have seen it of cream 

 color or yellow. Darker zigzag lines parallel to the median sutures, 

 with sometimes lozenge-shaped figures near the porif. zone. 

 Darker bands of color often extend from pole to pole. The 

 spines are short, slender, pointed, dark green at base, tipped with 

 red violet or orange. Anal system somewhat large. Sutural 

 pores minute or absent. 



Ambltpneustes griseus. Blainville. 



Test comparatively stout, somewhat depressed ; remarkable 

 for its broad poriferous zone, and the size of the anal system. 

 Sutural pores more distinct. The A. space narrower than in 

 A. ovum. Color, greenish yellow to grey. Spines stouter, and 

 less tapering than previous species ; light green or violet, tipped 

 with darker color or orange. This species has exactly the same 

 range as the former, but is the less common of the two, 



Ambltpneustes formosus. Valenciennes. 



Thin, ovoid, remarkable for the number and distinctness of the 

 sutural pores. Test brownish pink, with yellow porif. zones, 

 ornamented by dark brown lozenges. Spines, long, slender, pink 

 at base, darker at the top, or red or orange. Generally smaller 

 than A. ovum . The same habitat as the last, ' but more 

 common in Tasmania. Found also in New Zealand. 



