I 12 
TH. MORTENSEN, 
(Schwed. Südpolar-Exp. 
Fig. 17. Globiferous pedicellaria of Loxechinus albus. s %- 
» 18. Sphæridia of Sterechinus Agassizii. I5 °/i. 
» 19. Globiferous pedicellaria, large form, of Notechinus magellanicus. (Comp. Fig. 3.) 
s %. 
Plate XVII. 
Fig. i. Part of the abactinal side, with the apical system of Plexechinus Nordenskjöldi. 
The upper plates of the frontal ambulacrum were not quite distinct. 8 /i. 
» 
2. 
Part of the 
actinal side of Plexechinus 
Nordenskjöldi. 8 /i. 
» 
3 - 
Plexechinus 
Nord en skjöl d i. 
Side view. 
"A- 1 
» 
4 - 
» 
» 
Abactinal side. 2 /i.î Figs. 3 — 5 same specimen. 
» 
5 - 
» 
» 
Actinal 
» 2 /J 
» 
6. 
» 
» 
Abactinal 
» »■ s/i.l 
» 
7 - 
» 
» 
Actinal 
» 2, 5 /i.> Figs. 6 — 8 same specimen. 
» 
8. 
» 
» 
Side view. 
2 -A. J 
» 
9 - 
Part of the 
abactinal side, 
with the apical system, of a young Abatus cavernosus , 
1.9 mm 
.. length. 5 °/i. 
10. Amphipneustes Koehler /, young specimen from the marsupium; 2 mm. length. 
Same specimen as Fig. ix. z %- 
11. Amphipneustes Koehleri. Same specimen as Fig. 10. Actinal side. 2 %. 
Plate XVIII. 
Fig. i. 
» 2. 
» 3 - 
» 4. 
» 5 - 
» 6 . 
» 7. 
» 8 . 
» 9. 
» 10. 
» ii. 
» 12. 
Amphipneustes Koehleri; young specimen, 2 mm. length. Actinal side. 27 A- 
» » Same specimen as Fig. 1. Abactinal side. 27 /i. 
Abattis cavernosus ; young specimen, 1.5 mm. length, from the marsupium. Actinal 
side. 4S /i. 
» » same specimen as Fig. 3. Abactinal side. 45 A- 
Figs. 5 — 12. Plexechinus Nordenskjöldi. 
Valve of ophicephalous pedicellaria. 2 °%. 
» » tridentate » from the inside. (Comp. Fig. 11.) I7 %. 
» » triphyllous » 2 °%. 
Sphæridia. _ I7 %. 
Secondary spine. II5 /i. 
Filament of actinal tubefoot. The pigment omitted. I7 °/i. 
Valve of tridentate pedicellaria, side view. (Comp. Fig. 6.) I7 %- 
Ophicephalous pedicellaria. II5 /i. 
Plate XIX. 
Fig. i. Tridentate (bivalve) pedicellaria of Amphipneustes Lorioli. 35 /i. 
» 2. » » » , small form, of Amphipneustes Lorioli. 35 /i. 
j> 3. Valve of globiferous pedicellaria of Amphipneustes Koehleri. Side view. (Comp. 
Fig. 20.) 7 %. 
» 4. Sphæridia of Amphipneustes Koehleri. IIO /i. 
