550 CK'KRSWKLI, SIIKA1{EI{ AND DOROTHY .IORDAN LLOYD. 
EXPLANATION OF PLATES 30-32. 
Illiisti-ating tlie paper by Mr. Cressvvell Shearer and Miss 
Porotliy Jordan Lloyd. ‘‘On Aletliods of I’roducing 
Ai'tificial Parthenogenesis in Echinus escnlentus, 
and tlie Rearing of the Partheuogenetic Plutei through 
Metamorphosis.’^ 
Lettering. 
a. cil. cp. Anterior ciliated epaulette. uJ. a. Antero-lateral arm. an. 
Anus. CO?/. Cadomic sac. ec/n ?•. Echinus rudiment, la. Mouth. p.ciJ. 
ep. Posterior ciliated epaulette, pd. a. Postero-dorsal arm. ped. 
Pedicellaria. p>o. a. Postoral arm. pro. a. Preoral arm. st. Stomach. 
PLATE 30. 
All the figures refer to Echinus esculentus. 
Fig. 1. — Normal pluteus; dorsal aspect; 12 days old. X 100. 
Fig. 2. — Normal pluteus ; 4 days ; dorsal aspect, x 100. 
Fig. 3. — Partheuogenetic pluteus. Loeh’s method MgCh. ; 4 days. 
Highly ahnormal ; ventro-lateral aspect, x 100. 
Fig. 4. — Typical partheuogenetic i^luteus ; 25 days; dorsal aspect; 
liosterior ciliated epaulettes beginning to be cut off. Loeb's iiipjroved 
method. X 50. 
Fig. 5. — Partheuogenetic pluteus; 4 days; left lateral aspect. Loeb’s 
MgCL method, x 100. 
Fig. 6. — Partheuogenetic pluteus ; 4 days ; ventral aspect. Loeb’s 
improved method, x 100. 
Fig. 7 . — Parthenogenetic pluteus ; 5 days ; left lateral aspect. Loeb's 
method, x 100. 
Fig. 8 . — Parthenogenetic pluteus; Typical; 8 days ; dorsal aspect. 
Loeb's method, x 50. 
Fig. 9. — Parthenogenetic pluteus ; 45 days old ; ventral aspect. 
X 100. 
Fig. 10. — Normal pluteus; 22 days; dorsal aspect, x 50. 
PLATE 31. 
Fig. 11. — Young metamorphosed Echinus; ventral view; raised 
from egg fertilised with sperm. X 100. 
