578 BREYNIA. 



BREYNIA. 



Breynia Des., 1847. \c... ('. R. Ann. Sc. Nat . VIIT. 



Large Spatangoids with a thick tes< ; remarkable for the presence of three 

 kinds of fascioles not usually found associated in other Spatangoids. viz. 

 an internal, snbanal, and peripetalous fasciole. Large tubercles, deeply 

 sunken, are enclosed in a space formed by the peripetalous fasciole. The 

 internal fasciole causes an atrophy of the ahactinal pari of the petals, as 

 in Echinocardium. Gray suggested, in 1851, the propriety of making this 

 genus a subdivision of Echinocardium. The presence of a marked peri- 

 petalous fasciole, and the peculiar character of the large tubercles, would 

 seem sufficient (if any grounds are valid) among Spatangoids. to maintain at 

 present both these generic types. 



Breynia Australasiae 



Spatangus Australasiae Leach, 1813, Zo 1 Misc., II. p. G8. 

 ! Breynia Australasia* Gray, 1855, Cat, Rec. Ech. 



PL X I,/ - . ; 9; PL XXV. f. 32; PI. XXVI. f. :n. 



Test thick ; outline from above elliptical, slightly broader in the anterior 

 part, indented b\ a shallow, odd anterior ambulacral groove, truncated pos- 

 teriorly towards the act ino-toine. Apical system anterior, with lour genital 

 openings, placed close together; vertex posterior, ill front of the anal system, 



half-way between the inner angle of the ambulacra and the truncated pos- 

 terior edge. Seen in profile the ahactinal part of the test is nearlj horizontal, 

 arching very gradually towards the anterior edge, where the test drops sud- 

 denly. Actinal surface flat, with the exception of the slightly sunken sides 

 of the large polygonal actinostome, and the short keel at the posterior edge 

 of the small triangular actinal plastron. Peripetalous fasciole following the 

 outline of the test, except in the anterior interainhulacnun. before it crosses 

 the odd ambulacrum, where it makes a short rectangular step. The peri- 

 petalous fasciole is formed of a series of lozenge-shaped elongate links. The 

 internal fasciole is pointed posteriorly, it extends from the geometric centre, 

 with nearly parallel sides to its sudden crossing of the odd ambulacrum, at 

 one third the distance from the apical system to the edge of the test. The 

 apical portion of the anterior poriferous zones of the anterior lateral ambulacra 

 is completely obliterated by the internal fasciole. The pores of the odd am- 



