KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 58- NIO 9. 13 



except for a narrow ring of small, fenestrated plates along the inner börder, inside 

 the buccal plates, which are small and rounded. Otherwise the peristomial mem- 

 brane contains rather numerous bihamate spicules of somewhat elongate shape (Text- 

 fig. 3). At the base of the gills there are some delicate, very wide-meshed fene- 

 strated plates. The gills otherwise contain only few bihamate spicules. 



The colour of the test is quite different in the two species. While in T. deco- 

 rum it is uniformly olivegreen, it is in T. elegans greenish-white, the pore-areas 

 beautifully pinkish. 



The spines are whitish, with mostly three narrow bands of a 

 violet-red colour, the outer one the largest and most intcnsely coloured ; 

 this coloration is conspicuously different from that of T. decorum, 

 which has the spines banded with intense scarlet bands. The spines 



■ 



c 



near the peristome are flattened and distinctly widened at the tip; /, 



in T. decorum this character is much less conspicuous. In structural J 



characters the spines are otherwise alike in the two species. Fig- 3. Spkuies from 



The pedicellariae. As stated already the globiferous pedicella- braneof Twmtremä 

 riae (Pl. V, Fig. 3) are like those of T. decorum, having a pair of ele gans. 220 />. 

 distinct lateral teeth below the endtooth; sometimes there may even be tw r o teeth 

 on one side. They are generally quite numerous. Tridentate pedicellariae w'ere not 

 found. The ophicephalous and triphyllous pedicellariae do not differ from those of 

 T. decorum. Spicules are very scarce in the tubefeet as well as in the inner organs. 

 They are of the same slender, bihamate type as those of the peristome. 



There are 7 specimens from 45 miles W.S.W. of Cape Jaubert, 27 meters 

 (29/ VI. 1911). One of them is somewhat lighter coloured than the rest, but other- 

 wise all agree closely in all the features characteristic of the species. 



The differences betw r een the present species and T. decorum are, certainly, not 

 very important; still they appear to be quite constant, so that it can hardly be 

 doubted that we have here a distinct, well defined species. However, it is desirable 

 to have it compared with specimens of T. decorum of a corresponding small size. 



The largest specimen has the following measurements. 



Height 9,5 mm. Diameter 15 mm. Apical system 3,5 mm. Peristome 6 mm. 

 Ambulacral plates 21. Interamb. plates 17. 



7. Nudechinus darnleyensis (Woods). 



Echinus darnleyensis Tenishn Woods. 1878. The Echini of Australia. Proc. Linn. Soc. X. S. Wales, 



II, p. 165. 

 Gymncchinus » Th. Mortexsen. Ingolf Echinoidea. I, p. 110, 136. 



» De Meijere. »Siboga»-Echinoidea, p. 89. Taf. XVII. Fig. 275— 6, Pl. XXI, Figs. 



7, 23, 36. 

 » Tu. Mortensen. Siam-Echinoidea, I. p. 117. 



Nudechinus » H. L. Chark. Hawaiian a. o. Pacific Echini. The Pedinidae, . . . and Echino- 



metridae. Mem. Mus. Comp. Zool., Vol. XXXIV, No 4, 1912, p. 277. 



A single small specimen, 6 mm in diameter, from 45 Miles W.S.W. of Cape 

 Jaubert, 20 M. (10/VII. 1911). 



