ECHINOIDEA. I. 141 



all events, deserves a closer examination. There is, however, one feature left, from which important 

 contribntions to the classification mav be expected, viz. the larval forms. As almost all the species 

 belonging liere, are littoral forms, they mav all be supposed to have pelagic larvæ, and they will, no 

 doubt, show a great richness in forms. That the larva of Sphærcchinus is so different from those of 

 Echi>nis^) indicates, at all events, that very interesting things may be found here. 



Fam. Echinidæ. 



Subfam. Parechininæ. 

 II. Parechinus miliaris (Miill.). 



PI. II. Fig. 7. PI. XV. Figs. 6— 7, 11. PI. XVI. Fig. 15. PI. XVII. Figs. i — 2, 7-S, 10— 11, 14—15, 22-28. 



Principal synonyms: EcJimiis viiliaris Miill. 



Psannnccliiims miliaris (Lamk.). 

 Echiinis saxatilis O. F. Mull. 

 — virens Diib. Kor. 



Principal literatnre: Diiben & Koren: Ofversigt af Skandinaviens Echinodermer. p. 274. — 

 Agassiz: Revi.sion of Echini. p. 495. — Hoyle: Revi.sed List of Brit. Echinoidea {202). p. 417. — 

 Bell: Catalogue of Brit. Echinodernis. p. 150. With regard to the other extensive literatnre the reader 

 is especially referred to Bell' s Catalogne. 



It is not necessar>- to give a thorongh description of this well known species, I shall onl\- 

 refer to the works cited above. On PI. II. Fig. 7 is given a coloured figure of the animal; with regard 

 to the test I shall refer to PL XV. Figs. 6— 7, 11, where the apical area, an ambulacral and an interambu- 

 lacral area are represented. From these fignres it is clearly seen that the secondar)' tnbercles form 

 no regular longitudinal or transverse series, and that a primary tubercle is found on all the ambu- 

 lacral piates. The buccal membrane is richly provided with large, thick, irregular piates, between 

 which the naked skin is seen, especially on dried specimens; they are constructed as usual (PI. XVI. 

 Fig. 15; the figure represents one of the simplest piates from the outer edge of the peristome), con- 

 trary to what is the faet in P. inicrotiibcrculahis (Pi. XVI. Fig. 14) where they consist of a compact, 

 greeiiish calcareous mass with funnel-shaped holes. The piates inside of the buccal jalates are some- 

 what smaller than those outside and constructed in a far simpler way; they consist only of one layer 

 with some knobs on the upper side. The buccal piates carry numerous pedicellariæ, but no spines. 

 The gills contain small irregular calcareous piates. 



The pedicellariæ. The globiferous pedicellariæ (PI. XVII. Figs. i, 7, 23 — 24) are generally exceed- 

 ingly numerous, and form, as it were, a dense, white flue, especially on the abactinal side. The blade 

 is rather broad and flat, and the edges not connected by cross-beams across the inside. The edges are 

 not thickened, and project into — generally — 7 — 8 long, somewhat irregular indentations; the number 

 may vary between 5 and 10. There are often some more on one side than on the other. The stalk 



1) Th. Mortensen: Die Kchinodernienlarven der Plankton-Expedition. Krgebn. d. Plankton-E-vped. d. Hntnboldt- 

 stiftung. II. J. 1S9S. 



