MUSEUM OF COMPARATIVE ZOOLOGY. 147 
The following summary may be made of new figures, or new anatomi- 
cal details first figured :— 
1. Figures (Pl. I. Figs. 1, 2) of plutei of Ophiopholis older than that 
figured in Bull. Mus. Comp. Zodl., XI. 4, Fig. 23, and younger than 
adult. Figure (Pl. I. Fig. 3) of an ‘adult pluteus of Ophiopholis. 
2. Figures (PI. II. Figs. 5, 7, 8) of the umbilical connection of the bi- 
laterally symmetrical young with its parent. These differ from those of 
Max Schultze in showing the relation of this structure to internal organs. 
In Apostolides’ and Metschnikoff’s figures of the bisymmetrical larva 
this structure is not represented. Figure (Pl. II. Fig. 4) of a larva witha 
single asymmetrical pluteus spine. Figures (Pl. II. Figs. 13, 14) of the 
actinal and abactinal hemisome of a young Amphiura of an age between 
that figured by Ludwig on Pl. XI. Figs. 17, 23, and Pl. XI. Fig. 19. 
3. Figure (Pl. III. Fig. 20) of the actinal hemisome of a young 
Amphiura older than Ludwig’s Pl. XI. Fig. 18. This figure shows struc- 
tures purposely omitted in all Ludwig’s figures, viz. spines and club- 
shaped bodies, appendages of the second pair of adambulacral. Figure 
(Pl. ILI. Fig. 17) older than Ludwig’s Pl. XI. Fig. 19 and younger than 
his Pl. XI. Fig. 18, illustrating the formation of the first side plates 
of the arms. Figure (PI. III. Fig. 19) illustrating the relative situation of 
the dorsals. Dorsals are omitted in all Ludwig’s figures of the arm from 
the abactinal side. My figure is younger than, his Pl. XI. Fig. 21, in 
which a dorsal ought to be represented. Figure (PI. ILI. Fig. 15) show- 
ing the arm-joints or ambulacral plates of the arms zm situ and before 
coalescence. 
CAMBRIDGE, January, 1887. 
