72 THE VICTORIAN NATURALIST. 



4. Amblypneustes griseus, Blainv. 



Agassiz seems to voice the general opinion when he says 

 Amblypneustes is a very difficult genus, on account of its great 

 variability. It is a Southern form only. Four Australian species 

 are recognized by Agassiz in his Revision — namely, A. Jormosus, 

 griseus, ovum, and pallidiis. He is doubtful if ^?a/^irfits is distinct 

 from /ormosus. In the Challenger volume he records Jormosus 

 alone of the four, and the only locality where it was obtained was 

 East Moncoeur Island. Ramsay thinks griseus equals yb)*mosMs, 

 and that there are only two distinct species— yb?'mosws and ovum. 

 Tenison Woods, again, thinks pallidus and griseus are but modifi- 

 cations, not oi Jormosus, as Ramsay does, but of ovum. Duncan 

 says A. griseus is a very erratic species. There is not much that 

 is satisfying about these observations to help one in identification. 

 The examples that I have examined are none of them identical 

 with any of the species, and they vary in almost every point — 

 shape, colour, number of tubercles on a plate and their arrange- 

 ment ; while tiie size and number of sulural pores varies on the 

 same specimen. Still they all group round the griseus form, and 

 I consequently apply that name to them. The evidence at pre- 

 sent available seems to point to the existence of only one species, 

 with, perhaps, varieties due to conditions of life or geographical 

 position. 



Loc. — Washed up very commonly on all our beaches. Dredged 

 alive just outside Port Phillip Heads and in the South Channel ; 

 depth, 8-30 fathoms, by J. B. Wilson. The CAaZ/en^e?- specimens 

 identified as A.formosus came from East Moncoeur Island in 

 about 40 fathoms. 



5. HOLOPNEUSTES POROSISSIMUS, L. Ag. 



This usually dark-coloured Urchin seems to be not uncommon, 

 though Tenison Woods, a keen collector, as late as 1880 had 

 never seen a specimen of the genus on our coasts. In form 

 the species closely resembles Amblypneustes, being nearly 

 spherical, but the ambulacral pores, instead of being confined to 

 a narrow band, spread widely over the ambulacra, which are 

 broader than the interambulacra. 



There seems to be the same difficulty about the species of this 

 genus as there is about the last — at least, this is Ramsay's opinion. 

 The examples I have seen from Western Port are undoubtedly 

 the H. porosissitnus of Agassiz's Revision. 



Loc. — Thrown up in thousands at Shoreham, Western Port. 

 Dredged, Port Phillip Heads (Wilson). 



6. ECHINOCYAMUS, Sp. 



A small member of this genus, about 5 mm. in diameter, and 

 very depressed, occurs profusely on the Portsea beach, and I 



