AMBLYPNEUSTES GRANDIS. 329 



So far as can be determined this is the species figured by Valenciennes on 

 Plate 2 of the Zoophytes of the "Voyage of the Venus," as Echinus (Amblyp- 

 neustes) pallidus. As Mortensen has pointed out that figure is certainly not 

 pallidus, as that species is now understood. 



Excepting those recently collected at Westernport, Victoria, not one of our 

 specimens has a reliable locality label. These were purchased in Europe in 

 1870; five are labelled "New Zealand," two are labelled "Australia" and one 

 has no label. It is rather remarkable that other specimens of this species have 

 not been included among the many specimens of Amblypneustes and "Holo- 

 pneustes" received during the past few years at the M. C. Z. from New South 

 Wales and Victoria. It is apparently much less common at Westernport than 

 griseus, of which we received a good series, showing practically no diversity in 

 form or color. 



Amblypneustes grandis, 1 sp. nov. 



Plate 121, figs. 4-6. 



This is the largest species yet known, the type specimen having a horizontal 

 diameter of 70 mm. It is 49 mm. high, with the actinostome 18 mm. in diameter 

 and the abactinal system 13 mm. across. There are 33 interambulacral and 50 

 ambulacral plates in each column. The interambulacra are 26 mm. wide at 

 the ambitus. The ambulacra are 17 mm. wide but of this the two poriferous 

 zones together only occupy 6 mm. The pores are rather large and the arcs of 

 pores are quite oblique especially abactinally. The tuberculation of the test 

 is rather coarse for an Amblypneustes and it is virtually impossible to distinguish 

 between the primary and secondary tubercles. Each interambulacral plate 

 carries a horizontal series of these larger tubercles; on most of the plates, the 

 series bifurcates so that on the outer (adradial) half of the plate there are two 

 series, the whole group forming a narrow, elongated Y lying horizontally on 

 the plate; the stem of the Y contains 6 or 7 tubercles while each of the branches 

 consists of about 4. Besides these larger tubercles, there are some forty miliaries 

 scattered about all over the plate. Each ambulacral plate has a horizontal 

 series of four or five large tubercles, of which the innermost is smallest while the 

 one adjoining the poriferous zone is largest, its areola occupying about one half 

 the height of the plate; there are also a dozen or more miliaries on each plate; 

 of these two are placed side by side just above the largest tubercle, but their 



1 grandis = large and fine. 



