Von Buch on Crinoidea. 



13 



from the petiole, and in Echinus and the allied genera there 

 is no longer need of any corolla. 



But before the ocean-lily had opened and expanded its 

 arms, it moved on a short pedicel in the closed state in innu- 

 merable quantity, and only by frequent and highly varied at- 

 tempts did this rupture and expansion succeed. These closed 

 Crinoidea are still but little and imperfectly known ; they 

 deserve to be known, however, in every respect. For hitherto 

 no Encrinus has been found in the lower beds, and from 

 them there is formed an uninterrupted transition to the 

 Pentacrinus of the existing ocean. Hitherto these forms have 

 occurred almost exclusively in northern countries; in Sweden, 

 in Norway, and in the hills which bound St. Petersburgh on 

 the south ; and among them the Sphceronites are most fre- 

 quently met with. 



These are large round spheres, like oranges, with two poles 

 at the extremities. Linnaeus, in his journey through Oeland, 

 called them crystal-apples. Gyllenhahl, in an able investiga- 

 tion and description \\ t ] t J2), was however the first to recog- 

 nize their organic nature, and concluded that they might be 

 placed near to Echinus, on which account Wahlenberg ap- 

 plied to them the name Echinosphcerites, which Hisinger 

 has exchanged for the better one of Sphceronites. These 

 spheres are formed of numerous polyhedrous plates, gene- 

 rally hexagonal, perhaps of two hundred in one specimen. 

 Above opens a mouth, which is covered by a number of very 

 small moveable shields. Below, a petiole of thin pentagonal 

 articulations fixes the body to the soil. The plates are all per- 

 forated. In Sphceronites Aurantium these small pores stand in 

 a row from each angle of the polyhedron towards the centre, 

 yet not quite up to the centre itself. Each of these pores is 

 connected by a deep furrow with the adjacent plate, thus gi- 

 ving rise to rhombs, which always extend over two plates or 

 assulce; sometimes so prominently, that the rhombs them- 

 selves have been taken for assulce, and a species erroneously 

 named Sphceronites Granatum, because a similarity was found 

 in these rhombs to the surfaces of a granite crystal. But 

 Gyllenhahl had long before shown that the true polyhedrous 

 assulae bisect the rhombs in the shorter diagonal, and at right 

 angles with their striping. Pander, however, proves what had 

 escaped Gyllenhahl, that these stripes or grooves connect ten- 

 tacular apertures, as two pores do in the ambulacra of the 

 species of Cidaris. And therefore it is very probable that 

 Ischadites Koenigii (Murch. Silur. Syst. PI. 26. fig. 11.) is 

 only Sphceronites Aurantium, upon which an outline has been 

 given to the rhombs not belonging to them, and distorting 

 the whole. This discovery of Pander of tentacular passages, 



