Bd VI 4) 
THE ECHINOIDEA. 
107 
Plate V. 
Fig. 
4 
5 
6 
7 
8 
9 
10 
1 1 
12 
13 
14 
15 
Ail 
Arbacia crassispina Mrtsn. Actinal side. 
» » » Side view. 
» » » Abactinal side. Figs, i — 3 represent the same spe- 
cimen. 
» Dufresnii (Blv.). Abactinal side. 
» » » Side view. Same specimen as Fig. 4. 
» alternans (Troschel). Type specimen. Abactinal side. 
» » » » » Side view. 
» Dufresnii (Blv.). Actinal side. Same specimen as Figs. 10 — 11. 
» » » Side view. Same specimen as Fig. 12. 
Abactinal side. » 
africana (Troschel). Side view. 
» » Actinal side. 
Abactinal » 
Figs. 8 and 11. 
» 8 » 10. 
Fig. 9. 
the figures natural size. 
Plate VI. 
Fig. 
1. 
2. 
3 - 
4 - 
5 - 
6 . 
7 - 
9 - 
10. 
11. 
12. 
Loxechinus albus (Mol.). 
» » » 
» » » 
Abactinal side. 
Actinal » 
» » 
Abactinal side. 
Side view. 
-8. Sterechinus Neumayeri (Meissn.). Abactinal side. 
Sterechinus Agassizii Mrtsn. Abactinal side. 
» » » Side view. 
» ' » » Abactinal Side. 
» » » Actinal side. 
Figs, i — 2 and 5, figs. 3 — 4 and 6, and figs. 10 — 12 represent the same specimen in 
different views. 
All the figures natural size. 
Plate VII. 
Fig. i. Sterechinus Neumayeri (Meissn.). Abactinal side. 
» 2. » » » Actinal side. Same specimen as Fig. 1. 
» 3. » Agassizii Mrtsn. Abactinal side. 
» 4. » Neumayeri (Meissn.). Abactinal side. 
All the figures natural size. 
