129 fathoms, mud. (St. 192.) As mentioned above if is named Temnopleurus Hard- 

 wickii in the „Chall." Echinoidea p. 107. 



The relation between the two recent species of Opechinus thus far made 

 known and the fossil species is not to be made out with certainty, as the latter are 

 known from the tests alone; but it seems that 0. uariabilis is most nearly allied to 

 0. Rousseaui, whereas U. spectabilis differs from all the fossil species known (to me) 

 in the number of grooves, being thus the most specialized form of the genus. 

 Otherwise it has most likeness to O. Rousseaui, which species may then perhaps be 

 the ancestor of the recent species. 



I may here take the occasion to give some notes on the other Temnopleu- 

 rids, not mentioned above. 



Salmacopsis olivacea Döderlein. The globiferous pedicellariæ (PI. VI. Figs. 25, 

 30) have no lateral teeth , only a rounded knob on one side below the endtooth ; 

 the outer corners of the basal part are rounded, a little produced. The ophicephalous 

 pedicellariæ are like those of Opecb. variabilis; the triphyllous ones (PI. VII. Fig. 23) 

 have a few serrations in the edge of the lower part of the blade (always?). The 

 spicules are bihamate, very scarce in the tube feet; in the stalk of the globiferous 

 pedicellariæ some spicules may occur. The buccal membrane is quite naked except 

 the buccal plates and some bihamate spicules. The genital plates show the same 

 peculiar feature as Pleurech. variegatus, the outer part of the genital plates being 

 apparently separated off from the inner part by a transverse (straight) line. 

 The primary spines are smooth, ending in a mostly rather long central thorn, 

 surrounded at its base by a circle of smaller thorns. The secondary spines are 

 faintly thorny, a little swollen at the point; the central thorn is not prominent 

 above those of the outer circle. — Salmacopsis pulchellinms Yoshiwara I have not 

 seen. — The genus Salmacopsis evidently has the same relation to Salmacis as 

 Pleurechinus has to Temnopleurus. 



Mespilia globulus (L.). The globiferous pedicellariæ (PI. VII. Figs. 16, 22) are 

 exceedingly characteristic; there are 2 — 5 lateral teeth on either side of the blade, 

 the upper ones, which are directed outwards, being almost as long as the endtoolh; 

 the lower ones are mostly smaller and are gradually turned inwards. The blade 

 is open; the basal corners not produced. These (small) pedicellariæ occur in immense 

 numbers on the naked parts of the test together with a few triphyllous ones. Tri- 

 dentate pedicellariæ I have only found in the type specimen of M. Whitmœi (comp, 

 below); they are exceedingly small and simple, leafshaped (PI. VII. Fig. 47); the 

 ophicephalous pedicellariæ (PI. VII. Fig. 33) have the valves narrowed in the middle. 

 The triphyllous pedicellariæ (PI. VI. Fig. 17) are very small, with the apophysis 

 incompletely developed; generally some of the holes are elongate. In „Rev. ofEch." 

 PI. XXXVIII. Fig. 22 Ac.A.ssiz figures an „interambulacral abactinal pedicellaria" of 

 M. globulus, which looks (|uite problematic. I have never seen anything like it; if 

 it represents a globiferous pedicellaria of this species, the ügure is, as will be seen 



