OF NEW SOUTH WALES. 175 



fasciole and anal branches, sub-anal A. pores sending radiating 

 grooves through the centre of sub-anal area ; actinosome anterior 

 crescentic. Tuberculation within peripetalous fasciole coarse, 

 frequently consisting of primary tubercles. 



Metalta maculosa. 



Smaller than the following species, depressed, elliptical, indented 

 at anterior edge, truncated posteriorly, vertex posterior. Greatest 

 breadth across posterior petals, apical system more central, 

 narrow ambulacral petals, a shallow anterior groove which is 

 almost flush with test, except at the ambitus. Long., 43 to 78. 

 Lat., 36 to 63. Alt., 21 to 34. 



Rare at Port Jackson, and occasionally on the S. East coast. 



Metalia sternalis. Lamouroux. 



This large solid, swollen urchin, which is found in so many 

 collections (generally bleached), is of dark brown color, with 

 anterior apex, a broad zigzag peripetalous, and heart-shaped sub- 

 anal fasciole. The sub-anal plastron is distinguished by a fan- 

 shaped series of grooves, which converge from the fasciole. 

 Anterior petals form an acute angle with anterior groove. It is 

 sometimes met with, measuring 150 mil. in diam. Found through- 

 out the Pacific, and tropical Eastern Australia, the latter rarely. 



Genus 8. — Linthia, Gray, 1851. 



Fascioles peripetalous and lateral, the first angular ; the other 

 extending under the anal system. Anterior groove, shallow, and 

 broad ; anterior petals at right angles to th& odd ambulacrum ; 

 posterior narrow, long, and sunken. 



Linthta australis, Gray. 



Test thin, elliptical, angular, anterior groove descending to 

 the ambitus, posterior end tuberculated, apical system anterior, 

 vertex central. Long., from 38 to 61. Lat., 33 to 50, 25 to 39 

 mil. Common at times in South Australia and Tasmania. On 

 one occasion, thousands of them were thrown ob the beach at 



