OF NEW SOUTH WALES. 165 



Genus 7. — Echinus, Rondel, 1554. 



Urchins for the most part small, round, with small smooth 

 imperforate tubercles, in two principal vertical rows in the coronal 

 plates of both areas, the other tubercles smaller and irregular. 

 Actinosome small, cuts slight, membrane bare, with ten small 

 plates. Spines somewhat stout, sometimes equalling the test in 

 size. Pores in arcs of three, jaws weak, auricles slender. 



Echinus magellanicus, Phillipi, 



A small Echinus sent from Australia is supposed by Mr. 

 Agassiz to be the adult of this species which occurs generally in 

 Patagonia, Chili, and New Zealand. 



Echinus angulosus, Agass., is said to occur in Adelaide. 



Echinus Darnleyensis, n. s. 



This may be the Australian species which Mr. A. Agassiz 

 identified with E magellanicus* It is, however, quite different 

 from that species, and found hitherto only in tropical Australia. 

 Test small, circular, depressed, purplish, or livid, the tubercular 

 rows and porif. zones being lighter in color. Primary tubercles 

 in each area forming two vertical rows, the secondaries irregular, 

 but with a tendency to form vertical and horizontal rows in the 

 I. space, which is broader than the A. Sutures of coronal plates 

 distinct, with two very distinct secondaries on each, between the 

 primary vertical row of the I. and the porif. zone. Abactinal 

 system sunken. Gr. plates large, long, with two or rarely three 

 secondary tubercles irregularly placed on each, and Gr. pores large 

 in groove at the end ; ocular plates quite excluded, anal system 

 with many plates, the opening distinct and round. Actinal 

 surface rounded, depressed. Cuts slight. Membrane bare, with 

 ten rounded small openings surrounded by Pedecellariee. Opening 

 for teeth scarcely visible. Jaws rounded, stout, auricles forming 

 only slight thin processes, which do not meet. Pores in irregular 

 arcs of three, forming narrow irregular line. Spines rather long, 

 blunt, somewhat transparent, coarsely grooved, rose pink, dull 



* Revision of the Echinidce, p. 492. 



