72 
PROFESSOR E. RAY LANKESTER. 
Archerina is a duplex organism consisting of a Moner-like 
animal Protozoon, and a simple green alga, living together in 
constant association, or “Symbiosis.” But in my judgment 
there is no direct evidence, nor are there any grounds of 
analogy, for entertaining such a view as to the nature of this 
organism. 
EXPLANATION OF PLATE VII, 
Illustrating Prof. Ray Lankester's memoir on “ Archerina 
Boltoni,” nov. gen. et sp. 
Fig. 1. — Cyst of Archerina Boltoni, in optical section, a. Cyst wall. 
b. Granular contents, coloured green by chlorophyll. Nat. size = y^ooth of 
an inch in diameter. 
Fig. 2. — Another cyst, similarly viewed, a. Cyst wall. b. Protoplasm 
withdrawn from the cyst wall, and uniformly coloured by chlorophyll, c. Long 
tubular processes of the cyst. 
Fig. 3. — Surface view of a similar cyst. 
Fig. 4. — Optical section of another encysted Archerina, in which the colour- 
less protoplasm d is distinguishable from the two chlorophyll bodies b b. 
Other letters as in Fig. 2. 
Fig. 5. — Optical section of another cyst, showing uniformly short processes 
of the cyst wall, and green-coloured contents entirely free from the cyst 
wall. Letters as in Fig. 2. 
Fig. 6. — A deeper focussing of the specimen drawn in Fig. 4, showing the 
constricted vacuole e within the protoplasm. Other letters as before. 
Fig. 7. — Actinophryd-phase of Archerina Boltoni. Diameter of the 
sphere 2 oVg th of an inch, b b. Chlorophyll bodies, e. Vacuole. 
Figs. 8 — 12. — Central spheres of different specimens similar to Fig. 7, the 
radiating pseudopodia being omitted. They show various dispositions of the 
chlorophyll and of the vacuoles. 
Fig. 13. — Similar specimen to Fig. 7, showing two large chlorophyll bodies 
and a small vacuole. 
Fig. 14. — Similar specimen in a stage of tetraschistic division. The radiant 
protoplasm is omitted, and the pyramid of four incipient segmentation spheres 
is seen from one face. 
Fig. 15. — Four segmentation spheres resulting from a complete tetraschistic 
fission of the chlorophyll-ooloured body of an Actinophryd-phase of Archerina. 
