MUSEUM OF COMPARATIVE ZOOLOGY. 147 



The following summary may be made of new figures, or new anatomi- 

 cal details first figured : — 



1. Figures (PI. I. Figs. 1, 2) of plutei of Ophiopholis older than that 

 figured in Bull. Mus. Comp. Zo'OL, XI. 4, Fig. 23, and younger than 

 adult. Figure (PI. 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 (PI. II. Fig. 4) of a larva with a 

 single asymmetrical pluteus spine. Figures (PI. 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 PI. XI. Fig. 19. 



3. Figure (PI. III. Fig. 20) of the actinal hemisome of a young 

 Amphiura older than Ludwig's PI. 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 

 (PI. III. Fig. 17) older than Ludwig's PI. XL Fig. 19 and younger than 

 his PI. XL 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 PI. XL Fig. 21, in 

 which a dorsal ought to be represented. Figure (PI. III. Fig. 15) show- 

 ing the arm-joints or ambulacral plates of the arms in situ and before 

 coalescence. 



Cambridge, January, 1887. 



