ECHINOIDEA. II. 



151 



cellariæ were hitherto very insufficiently known; a few figures are given iu Revision of Kchini ■ 

 PL XXV. 29— 30 and PI. XXVI. 19, and Koehler (Op. cit. PI. 4. 14) gives a fignre of one kind of pedi- 

 cellariæ. I have found globiferous, rostrate, tridentate and triphyllous pedicellariæ, bnt no opliicephalons. 

 The globiferons pedicellariæ (PI. XVII. Figs. 12, 47) are rather like those of cordatum, only the blade 

 is generally more elongate (thongh not always so elon- 

 gate as in the fignred valve), and the basal part is nar- 

 rower. 3 — 4 teeth are foiind on either side of the term- 

 inal opening, and there may be one in the middle of 

 the onter edge; the terminal opening may sometimes 

 be qnite covered by the teeth. i^s is nsual the valves 

 are covered by a thick skin (PI. XVII. Fig. 47); the stalk 

 is rather thick and compact, knotted, with a distinct 

 thickening above and below, the latter withont free 

 projecting rods. -- The Fig. 19. PI. XXVI of Revision 

 of Echini , in the explanation of piates termed an open- 

 headed actinal« pedicellaria , evidently represents the 

 val\'e of a globiferons pedicellaria. — The rostrate pedi- 

 cellariæ are rather large and very characteristic (PI. X\'II. 

 Figs. 3, 52); the valves are coarsely dentate along the 

 side edge.s, the point, which is more or less ronnded, 

 finely serrate. They reach a rather considerable size, 

 ca. I — i-2'""i length of head. The Fig. 29, PI. XXV of 

 i. Rev. of Ech. ( long-headed ■ pedicellaria), as well as the PI. 4. Fig. 14 (pedicellaire gemmiforme) of 

 Koehler (Op. cit.) evidently represent this form. Anything nearly resembling the PI. XXV. Fig. 30 of 

 Rev. of Ech. I have not seen. 



The tridentate pedicellariæ occnr in two, not very sharply distingnishable forms; the one 

 (PI. XVII. Fig. 2) has slender, leafshaped valves, the larger ones joining only in the onter half; the 

 lower part is more or less coarsely serrate, the basal part rather narrow. The other form (PI. XVII. 

 Fig. 19) has short valves, generalh- a little inrolled in the lower part, and sometimes ending in a dis- 

 tinct tooth. This form to some extent recalls the form, which I have termed rostrate pedicellaria in 

 Ech. flavcscens — and it is, indeed, rather difficnlt to determine with certainty to which kind it ought 

 really to be reckoned, the rostrate pedicellariæ being, as repeatedly poiiited ont, essentially a special 

 form of tridentate pedicellariæ. — The triphyllous pedicellariæ (PL XVI. Fig. 16) are rather like those 

 of cordatuvi, with similar teeth inside along the edge of the blade. — Spicules seem to be almost 

 whoUy wanting in the tnbefeet, and no large spicules are found below the disk of the frontal tubefeet 

 which are otherwise wtll developed and like those of cordahtm. 



Fig. 25. Apical area of Echiiiocardium inedito'ranctiui 



4 T. 



After the revision of the species of Echiiiocardium given here it will perhaps not be found 

 useless to give an anal}tical table of all the species hitherto recognized with certainty. 



