KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 58. N:0 9. 11 



Although very broad in themselves the sutural grooves are made to look even 

 much broader through the coloration of the test. The ground colour is dark violet, 

 the grooves white. But then a white line of the same width as the groove continues 

 from each groove along the middle of the opposite plate unto the tubercle 

 adjoining the primary one, the dark violet colour being confined to the edges of the 

 grooves, where it occupies a band hardly as wide as the groove. This gives the 

 impression that the groove goes across the whole median part of the area, from 

 primary tubercle to primary tubercle, and the test gets a most peculiar ladder-like 

 appearance, to which the species name scalaris refers. 



The apical system does not present any conspicuous features. The ocular 

 plates are all exsert. There is a series of tubercles along the inner edge of the 

 genital plates, making a complete circle round the anal area. The genital pores are 

 rather large. The plates of the periproct are small, the anal plate hardly discernible. 



The peristome is entirely naked, without pedicellariae or spines on the buccal 

 plates. Inside the buccal plates it contains numerous small fenestrated plates. 



The spines are of a red-violet colour, not banded. The colour is lighter at the 

 base and the very tip whitish. The spines near the peristome are flattened and a 

 little widened towards the point, very slightly curved. The spines are all very short, 

 only ca. 5 mm long. Nearly all of them have a curious appearance; from a sharply 

 limited ring about the middle of the spine it becomes distinctly thinner and 

 lighter coloured. This is due to the fact that they have been broken and regene- 

 rated. Sometimes they have been broken and regenerated twice. Either the spines 

 of this species must be exceptionally brittle, or this specimen must have been exposed to 

 an unusually rough treatment during life. 



Pedicellariae. The globiferous pedicellariae (Pl. V, Fig. 17) have no lateral 

 teeth, only a small knob-shaped prominence below the endtooth. The corners of 

 the basal part are not prominent. The glands are double, as usual in the Temno- 

 pleurids. Tridentate pedicellariae were not found. The ophicephalous pedicellariae 

 (Pl. V, Fig. 14) are deeply sinuate along the edge of the blade. The triphyllous 

 pedicellariae (Pl. V, Fig. 8) present no characteristic features. 



The spicules are typical bihamate, very scarce in the tubefeet, rather numerous 

 in the gills. The peristomial membrane hardly contains a single spicule and also 

 the internal organs are devoid of spicules. 



The present species is very distinct from any other species of Temnopleurus 

 hitherto described and does not appear to be closely related to any of them. While 

 in the case of several species it is almost a matter of convenience, whether they 

 should be referred to the genus Temnopleurus or to Sahnacis, there can be no doubt 

 about the generic position of the present species. It is a typical Temnopleurus. 



In his paper on the Echinoderms of the Western Australian Museum H. L. Clark 

 mentions a pair of specimens, bare tests, of a Temnopleurus, which he thinks represents 

 a new species. He gives no description, except of the colour, which is dull green, 

 with the median ambulacral and interambulacral areas cream-coloured. Judging there- 



