ECHINOIDEA. I. 141 



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

 contributions to the classification may be expected, viz. the larval forms. As almost all the species 

 belonging here, are littoral forms, tliL\- nia>- all be supposed to have pelagic larvse, and they will, no 

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

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



Fam. Echinidae. 



Subfam. Parechininae. 

 II. Parechinus miliaris (JMiilL). 



PI. II. Fig. 7. PI. XV. Figs. 6-7, II. PI. XVI. Fig. 15. PI. XVII. Figs. 1 — 2, 7-8, 10—11, 14—15, 22—28. 



Principal synonyms: Ec/iiinis miliaris Miill. 



Psavnihcliiiiiis miliaris (Lamk.). 

 Echinus saxatilis O. F. jMiill. 

 — virrns Diib. Kor. 



Principal literature: Diib en & Kor en: Ofversigt af Skandinaviens Echinodermer. p. 274. — 

 Agassiz: Revision of Echini, p. 495. — Hoyle: Revised List of Brit. Echinoidea (202). p. 417. — 

 Bell: Catalogue of Brit. Echinoderms. p. 150. With regard to the other exten.sive literature the reader 

 is especially referred to Bell's Catalogue. 



It is not necessary to give a thorough description of this well known species, I shall only 

 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 PI. XV. Figs. 6— 7, 11, where the apical area, an ambulacral and an interambu- 

 lacral area are represented. From these figures it is clearly seen that the secondary tubercles form 

 no regular longitudinal or transverse series, and that a i3rimar\- tubercle is found on all the ambu- 

 lacral plates. The buccal membrane is richly provided with large, thick, irregular plates, 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 plates from the outer edge of the peristome), con- 

 trary to what is the fact in P. )iiicrotuhfrcnlatus (PI. XVI. Fig. 14) where they consist of a compact, 

 greenish calcareous mass with funnel-shaped holes. The plates inside of the buccal plates are some- 

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

 with some knobs on the upper side. The buccal plates carr>- numerous pedicellaria;, but no spines. 

 The gills contain small irregular calcareous plates. 



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

 ingly numerous, and form, as it were, a dense, white flue, especialh- 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 



I) Th. Mortensen: Die F;chinodernienlarven rler Plankton-Expedition. Ergebn. d. Plankton-Exped. d. Iluuiboldt- 

 stiftung. II. J. 1S98. 



