556 ECHINOBRISSUS RECENS. 



trie ; anal system placed in a more or less sunken furrow. Actinal system 

 eccentric, pentagonal, or transversely elliptical. Floscelle rudimentary ; no 

 well-marked bourrelets. 



Echinobrissus recens 



! NticleoUtes recens Er»v. 1836, Cuv. Regn. An. Ed. 111. 



1 Echinobrissus recens D'Orbig., 1854, Rev. Mag. Zool., p. 24. 



PI. XIV. f. 2-4; Pi. XXP.f. l-z ; PI. XXXVIII. f. so -Si. 



Test stout, depressed : outline from above somewhat rectangular, rounded 

 anteriorly ; greatest breadth across the posterior extremity of the posterior 

 petals, angular posteriorly ; posterior edge scarcely indented by anal furrow. 

 Vertex nearly central ; apical system anterior to vertex; anterior petals ex- 

 tending nearly to the edge of the test ; posterior pair reaching somewhat more 

 than half the distance from the apex to the posterior edge. Poriferous zones of 

 uniform breadth, diverging slightly, so as to leave the extremity of the petals 

 somewhat open ; pores of both zones round, of uniform size, irregularly 

 conjugated ; outer lows extending to the actinostonie from the extremity 

 of the petals ;. interporiferous spaces broader than the poriferous zones. 

 broadest in the anterior petal. Petals Hush with the test, posterior pair the 

 longest; four genital pores, posterior scarcely more distant than the anterior 

 pair. Anal furrow reaching vertex; anal opening longitudinally elliptical; 

 posterior edge nearly on a level with the v<\>j:c of the test ; sides of groove 

 very gradually rounded. In one of the specimens of the .Tardin des Plantes 

 the anal membrane is well preserved {/'/. XIV. f. 2, 3) ; there is a lame 

 outer row of plates round the posterior edge, with smaller ones extending 

 towards the nearly circular anal opening, situated at the top of the anal 

 system ; the plates immediately round the anal opening are small, closely 

 hut irregularly packed, becoming somewhat larger again, near the upper 

 part of the anal system. The continuation of the petals towards the acti- 

 nostonie is well seen in PI. XIV. f. ■!, 4, — interior views of the test. 



The tuberculation is large ; the tubercles more closely packed on the 

 central part of the plates; on the edges near the sutures the miliaries are 

 more numerous, forming indistinct, irregularly shaped lozenge figures, parallel 

 with the longitudinal sutures of the plates. The tuberculation of the anal 

 furrow is reduced to miliary granulation. On the lower surface the tubercles 

 are distant in the posterior interambulacral space, but closely crowded in the 

 swollen edge of the posterior interamhulacra. The actinostonie is sunken ; 



