OF NEW SOUTH WALES. 155 



Heterocenteotus mammillatus. Klein. 



The large " pencil fish," well known to collectors. It is found 

 throughout the Pacific, and four or five specimens were dredged 

 by the " Chevert " off Darnley Island. This is the first time an 

 Australian habitat has been ascertained. Ten to twenty fathoms 

 on sandy mud. 



This species must not be confused with one very like it from 

 the Mauritius. " The secondary spines of H. mammillatus" 

 says Mr. A. Agassiz,* form a sort of loose pavement, somewhat 

 similar to that covering Colobocentrotus ; they cover the whole 

 test, are small, short, usually flaring and truncated at the ex- 

 tremity ; while in H. trigonarius they are bevelled. 



Genus 2. — Echinometra, Rondel, 1554. 



Test thin, elongate, tubercles large imperforate, not crenulate, 

 slightly smaller in the A. area. Poriferous zone moderately broad 

 pores in very prominent arcs of many pairs. Actinosome large, 

 cuts shallow, often broad. Jaws very powerful (they are com- 

 paratively small in Heterocentrotus) auricules very massive. 

 Actinal membrane with 10 buccal plates, on which there are 

 usually clusters of spines. Spines quite stout, somewhat long, 

 and longitudinally striated. 



Echinometra lacunter, Leske. 



A very variable species, found abundantly under stones in all 

 tropical Eastern Australia. It is not mentioned as Australian in 

 Mr. Agassiz very extensive lists. Mr. Macleay brought specimens 

 from Cape Grenville, Endeavour River, Darnley Island, and New 

 Guinea. The largest specimens were scarcely two inches in the 

 longest diameter. The colour of the spines varied from purple to 

 straw colour, but the most were banded, and the whole appearance 

 of the test is very much like a small porcupine. The spines 

 are swollen, generally falling off when the test is dry, and the 

 ground color of the shell is dull violet. 



* Revision of the Echini, p. 429. 



