NOTES. 45 



more beautiful than in the adult, in some the primary spines 

 often exceeding three times the length of the diameter of the tests, 

 are of a rich purple or claret color beautifully ringed with white. 

 The specimens alluded to were dredged off a sandy and rocky 

 bottom in 8 fathoms of water, near the "Bottle and Grinds " 

 reef, in Port Jackson, and also off Shark Reef and Bradley's 

 Head, many secreted in the folds and angles of large Sponges 

 and Ascidians. The spines of the adults are of a rich uniform 

 dark claret color, very brittle and hollow. These Urchins frequent 

 the reefs and rocky shores just below low-tide mark, where they 

 obtain their food ; they progress with considerable rapidity for 

 an Urchin when once disturbed, until they find a secure retreat 

 in some crevice of the rocks, from whence it is difficult to remove 

 them without destroying either the spines or test. I notice that 

 the spines of those from the outside reefs, where they are 

 exposed to the wash of the sea, are shorter and somewhat 

 rounded at the tips, while those taken from the quiet waters 

 inside have larger and more pointed spines. They are gregarious, 

 many being found together, and frequent shallow waters. The 

 broken spines are readily repaired, the new tips growing rapidly. 

 It is this species, perhaps more than any other Urchin, that 

 becomes food for the Port Jackson Shark, Heterodontus 

 galeatus ; the more common species H. plnlipi also occasionally 

 'feeds on them, the teeth of both species becoming stained of a 

 beautiful pink or rose color. These Sharks frequent the 

 reefs where the Echini abound, and it is quite probable many 

 other species of Echinodermata supply them with food, their 

 strong dorsal spines are frequently ground down to the surface 

 of the fins, by their searching for food under the shelving rocks. 

 The peculiar pigment or dye contained in the spines and within 

 the test itself is worthy of investigation. I know of no other 

 species on our coast which has this peculiarity. In cleaning 

 the tests the fingers and nails become stained with the pigment, 

 which is very difficult to remove. 



ECHINOTHEIX CALAMARIS. 



I have never seen any authentic specimen of this genus from 

 the N. S. Wales coast. 



HETEROCENTROTUS MAMMILLATUS. 

 ECHINOMETRA LACUNTA. 



The former is a very common species throughout the Pacific 

 Islands ; the latter, although found so near at hand as Lord 

 Howe's Island, has not, as far as I am aware, yet been obtained 

 on the coast of 1ST. S. Wales, although we have specimens from 

 Port Denison, and I have heard of its being found as far south 

 on the coast as Wide Bay, in Queensland. 



