340 Mr. W.C. Hewitson on new Species of Hesperide. 
nucleolulus and its irregular, variable form: »', nucleus; 7’, 
nucleolus; »'’’, nucleolulus. 
Figs. 12, 18. More advanced stages of the development of the ovum, asso- 
ciated with an enlargement of the ovum. 
Fig. 14. A second observed case of a nucleolus in process of division : 7", 
nucleolus. 
Fig. 15. A nucleolus (n'’), much magnified, with a nucleolulus (x'") in 
the middle and an aureole of five small granules. 
Fig. 16. The apex of a stem of Obelia flabellata, in which the ccenosare 
has become detached as a cylinder with a cavity. : 
Fig. 17. A hydrotheca in which the ccenosare has formed, instead of a 
cylinder, a sphere with a cavity, ectoderm, endoderm, and pe- 
risarc, 
PLATE XIV. 
Fig. 1. Leptoscyphus Grigoriewi, nov. sp., magnified, drawn with the 
camera lucida. 
Fig. 2. Two varieties presented by the hydrothecee of Leptoscyphus Gri- 
gortewi, more highly magnified. Drawn with the camera 
lucida. 
Fig. 8. Sertularia albimaris, nov. sp., principal stem and lateral branches. 
Enlarged ; drawn with the camera lucida. 
Fig. 4. A colony of Sertularia albimaris, natural size. 
Fig. 5, Portion of the hydrorhiza of the same, much enlarged (camera 
lucida): a, the spines; 0, the vertical partitions formed by the 
lateral walls of the tubes, which are joined in growing. 
Fig. 6. Sertularella gigantea, mihi, natural size. 
Fig. 7. The same, enlarged. 
PLATE XV. 
Fig. 1. A very fine colony of Polyserias Hinckswi, nov. gen. et sp. 
Fig. 2. Part of a stem of the same Hydroid, enlarged (camera lucida). 
Fig. 3. A mature gonotheca of Polyserias Hincksu. 
Fig. 4. A young gonotheca of the same. 
Fig. 5, Polyserias mirabilis, with immature gonothecee (camera lucida). 
Fig. 6. A mature gonotheca of the same Hydroid. 
Fig. 7. Part of a colony of Oorhiza borealis, nov. gen. et sp., enlarged, 
from a sketch by M. Wagner. 
Fig. 8. Sporosacs of Oorhiza borealis, issuing from the hydrorhiza. 
Fig. 9. Tip of a tentacle of Oorhiza borealis with pseudopodium-like fila- 
ments and red pigment grains (eye-pigment). 
Fig. 10. A body on a peduncle, moving like an Ameba, and giving origin 
to filaments. 
Fig. 11, Another tip of a tentacle, to show the arrangement of the fila- 
ments. 

XXX VII.—Descriptions of twenty new Species of Hesperide 
from his own Collection. By W. C. HEwirtson. 
Plesioneura Tola. 
Alis utrinque nigro-fuscis: anticis fascia media, regulari, nervis 
albis quinquepartita, nivea. 
Both sides dark brown. Anterior wing crossed in the 
