ECHINUS ELEGANS. 491 



Echinus elegans 



'.Echinus elegans (Dub. o. Kor.), 1844, Skand. Ech. 



PL VII". f. 4. 



Recognized from its congeners by the beautiful vermilion bands, extending 

 from the apex towards the ambitus ou both sides of the bare median vertical 

 line, both in the ambulacral and interambulacral spaces, separated by the 

 broad, yellowish poriferous bands. The principal rows of rather small pri- 

 mary tubercles stand out in bold relief from the plates, which carry from five 

 to six secondary tubercles in the interambulacral, and are crowded by mil- 

 iaries, especially near the ambitus ; in the ambulacral the miliaries are as 

 numerous, but there are only one to two secondaries. The test is thin ; the 

 genital plates are large ; edge near the anal system closely covered by mil- 

 iaries and secondaries. The primary spines are long, slender, often bril- 

 liantly colored, red, green, or tipped with white, green at base, or pink at, 

 the extremity. The secondaries are sometimes the color of the primaries, 

 but more usually of a uniform tint. In very large specimens alternate pri- 

 mary tubercles in both areas of the main vertical row are frequently resorbed. 



Norway ; Mediterranean. 



Echinus esculentus 



Echinus subglobosus LlNN. 1745, Fauna Suec. 

 Echinus esculentus Linn. 1758, Syst. Nat. 



pi. rir.f.7. 



The coronal plates are broad, thinly covered by miliaries, covered with 

 tubercles nearly uniform in size, slightly smaller towards the median line, 

 with a large well-defined scrobicular and small but sharply defined tubercle 

 arranged in irregular horizontal lines. The poriferous zone is broad. 

 The median ambulacral space is about twice as broad as the poriferous zone ; 

 the edge nearest the poriferous zone is flanked by a closely crowded vertical 

 row of primary tubercles as large as any of the median interambulacral 

 region ; the rest of the plate is covered by tubercles and miliaries arranged 

 as in the interambulacral zone. The genital plates are heptagonal ; madre- 

 poric genital much larger than the others, covered with large secondary 

 tubercles like those of the test ; ocular plates well separated from the anal 

 system by the genital plates. Actinal membrane with plates irregularly 

 scattered in the continuation of the ambulacral system. The spines are short, 



