58 



thorn surrounded by smaller ones etc. They are especially of importance in the 

 genera Pleurechiims and Amblypneiistes. 



The buccal membrane is mostly quite naked, with the exception, of course, 

 of the buccal plates; only in Triyonocidaris, Prionecliinus and Hijpsiechinus it is 

 covered with large plates. There are some small irregular plates just round the 

 mouth, otherwise no plates or only a few, but mostly numerous bihamate spicules; 

 where such plates are found outside the buccal plates, they are mostly placed 

 opposite to the gills, carrying some pedicellariæ. Otherwise pedicellariæ are very 

 scarce or quite wanting on the buccal plates; neither do spines occur thereon. 

 A very curious feature is found in the new species of Pleiirecliimis, PI. Düderleini, 

 described below, there being only five buccal plates and five buccal tube- 

 feet. It reminds one of Prionecliinus and Hypsiechinns, which have likewise only 

 five buccal tubefeet (but ten buccal plates) in the young stages; but in PI. Dlkler- 

 leini this condition is permanent. 



In the collections brought home by the Siam-Expedition the Temnopleurids 

 are very well represented, viz. by the species: Teninoplennis loreuniaticiis, Salmacis 

 sphœroides, f. typica, S. l>icolui\ var. rarispina, S. virgiilala, S. dii.ssiiniieii, Pleurecliinus 

 Döderleini n. sp. and PI. siainensis n. sp. Further specimens of Temnopleurus Reevesii 

 are found in the Museum of Copenhagen, from the Gulf of Siam (Salmin). 



6. Temnopleurus toreumaticus (Klein). 



PI. VI. Figs. 8, 14, 22, 49. PI. VII. Figs. 3, 28. 



Cidaris toreumalica. Ki.kin. 1734. Naturalis dispositio Echiiiodermatiim. p. 17. PI X. fig. E. 

 Temnopleurus toreumaticus. L. Ao.issiz & Dksoii. 184(). Catalogue rais. des Kch. |>. 31)0 (5fi). 



— liei/naudi — — — — -- 

 Toreumalica yranulosa Gray. 185r). An arrangement of the F'amilies of licliinidæ, with descriptions 



of some new Genera and Species. Proc. Zool. Soc. 1855. p. 3il. 

 Temnopleurus toreumaticus. A. Aoassiz. 1872. Ilev of Echini, p. Ififi, 4(i3. PI. VIII. a. fig. 4 5. 



— granulosus. Bki.l. 1880. On some genera and species of the Teinnopleuridie. Proc. Znol. 



Soc. 1880. p. 424— 25. 



— toreumaticus. Duncan. 1881. On some points in tlic Morphologj' of the test of the 



Temnopleuridæ. J. Linn. Soc. XVI. p. 350. PI. VIII. figs. 1(1 14. 



— — DÖDEULEIN. 1885. Seeigel v. Japan u. den Liu-Kiu-Inseln. p. 15. 



— — Ives. 1891. Echinoderms and Arthropods from Japan. Proc. Acad. Nat. Sc. 



Philadelphia. 1891. p. 214. 



— — Bedford 1900. Ecliinod. from Singapore and Malacca, p. 280. 



Non: Temnopleurus Reynaudi. A. Agassiz. Rev. of Echini (= Reevesii Gray). 



— — toreumaticus Sladen. 1878. On the Asleroidea and Echinoidea 



of the Korean Seas. J. Linn. Soc. XIV. p. 4;{8. 

 (== Pleurechinus varieyatus Mrtsn.). 



— — — Bell. 1884. Echinodermata „Alerl"-Exped. p. 119. 



— — — De Meuere. 1904. Siboga-Echinoidea. p. 80. 



