BY REV. J. E. TE^ISON-WOODS, F.L.S. 285 



broad and deeply impressed. It encloses a rhomboidal area 

 which has an obtusely angular anterior apex, a very broad 

 rounded posterior base, and is rounded at the ends of the anterior 

 petals. It re-enters slightly at about the same obtuse angle 

 above and below the anterior petals. All the petals are rather 

 broad, deeply sunken in the middle, and becoming flush with 

 the test at the ends. The depression extends beyond the line of 

 pores at each side. The anterior ones are the shortest. They 

 are at right angles to the mesial line, and extend about half-way 

 to the edge of the test. The posterior petals almost touch at the 

 genital pores. They do not diverge very much posteriorly, and 

 though longer are not quite so deep or so wide as the anterior 

 pair. The pores in all are large, wide, and conspicuous. There 

 are four rows in each petal, quite distinct and separated from 

 each other by a distinct raised broad ridge. There are about 15 

 pores on each row in the posterior petals, but they become rather 

 faint at the attenuated apical ends. There are 12 in each row in 

 the anterior petals, which are quite distinct, but a little smaller 

 at both ';he ends, which are rounded and not attenuate. The 

 whole of the test shows uneven undulations, the sutures of the 

 plates are faintly visible in places, and they form a double 

 zigzag diverging line of suture anteriorly from the apex. 

 Long. 64, lat. 58, alt. 35. Posterior petals, long. 19£, lat. 5. 

 Anterior petals, long. 15, lat. 6. Alt. of test at anal end, 30. 



This very interesting urchin has been found only at Moreton 

 Bay, where it is sometimes washed ashore. It has never 

 been found alive or with the spines, and being very brittle 

 is nearly always broken in the surf. There is only one other 

 species of the sub-genus Bhynobrissus, which occurs in the 

 Chinese seas. The differences of this species from ours are : — 

 The apex is posterior and not elevated above the rounded outline 

 of the surface. The peripetalous fasciole is oval. The petals 

 are much smaller, narrower, and more divergent. The pores are 

 conjugate. The abactinal tubercles are not uniform, and are 



