OF NEW SOUTH WALES. 167 



Genus 8. — Evechinus, Verril, 1871. 



Very like Hipponoe ; circular, somewhat depressed, tubercles 

 very unequal, primaries in regular vertical rows, secondaries 

 irregularly grouped round their bases. Porif. zone broad in three 

 irregular vertical rows. Actinosome small ; cuts slight : spines 

 stout, tapering, rather short, very unequal in size. 



Evechinus australle, N.s. Test thin, circular, or in small 

 specimens obscurely pentagonal, depressed. Profile regularly 

 arched, actinal region very slightly sunken. A. a little broader 

 than I. Tubercles of A. slightly smaller than I. both surrounded 

 by an irregular ring of secondaries and milliaries. Two vertical 

 rows of primaries in the A. area, four in the I. at the ambitus, but 

 the two inner ones diminishing in size at the actinal and abactinal 

 region, while the two outer ones preserve their size and regularity 

 to the edge of both regions. Porif. zone wide of three vertical 

 rows. The two outer ones a regular vertical row of pairs, the 

 middle an irregular arc of three pairs. Zones narrowing at 

 abactinal region but only slightly at the actinosome. The three 

 rows separated by two irregular rows of secondary tubercles with 

 milliaries scattered between. Abactinal area wanting in all the 

 specimens seen by me. Actinal region somewhat large, penta- 

 gonal ; cuts deep, circumscribed by a raised margin. Auricles 

 high, narrow, triangular and scarcely united over the large 

 foramen ; no connecting ridges. 



Three specimens with no information as to habitat were found 

 in the Sydney Museum, but I have every reason to believe they 

 came from the N. S. Wales coast. They are bleached and 

 without spines, the anal system has disappeared. The following 

 are the dimensions in millimetres : — 



