STRUCTURE AND DEVELOPMENT OP LOXOSOMA. 
333 
gland-cells, and two ganglion-cells {gac.) in connection with their respective 
sense cells {sc.). 
Fig. 8. — L. crassicauda. Part of the edge of the calyx (living) in 
optical section. 
Fig. 9. — L. Tethyse. A portion of the stalk, from a glycerine prepara- 
tion, previously treated with palladium chloride. The upper half of the figure 
shows the ectoderm in surface view, the lower half representing an optical 
section of one of the rows of cells. 
Fig. 10. — L. crassicauda. Connective-tissue cells, from the side of the 
stomach. (From a glycerine preparation.) 
PLATE XX. 
Fig. 11. — L. crassicauda. A median longitudinal section of an entire 
individual ; only the ventral end of the stalk is involved by the section, which 
passes through the whole of the alimentary canal, through the ganglion (ga.), 
and two of the tentacles {(.). At the base of each of the latter, on its outer 
side, is seen a small accumulation of nuclei (ectodermic), representing all that 
can be made out in the section of the crumpled edge of the vestibular fold, 
which during retraction of the tentacles completely encloses the vestibular 
cavity. The animal was killed, during extension of the tentacles, by boiling 
corrosive sublimate (a saturated solution in sea water). 
Fig. 12. — Pedicellina echinata. A horizontal section of a female con- 
taining embryos {em.) in the brood pouch, which is lined by a glandular 
epithelium {ebp.) thrown into numerous folds. The oesophagus («?.) and 
intestine {ini.), the ganglion (ga.) and the ovaries (ov.) with their ducts {ovd.) 
are also represented. The figure was combined from two series of sections. 
Fig. 13. — Loxosoma Tethyee. A horizontal section through a male 
individual, killed with the tentacles extended in boiling sublimate, tes. Testis. 
vd. Vas deferens, vs. Vesicula seminalis. 
Fig. 14. — L. Tethyse. Horizontal section of a female, with tentacles 
retracted (the figure is combined). Ganglion {ga.), ovaries {ov.), and oviducts 
{ovd.) are represented. In the left ovary is indicated the process of the 
absorption of several of the primordial ova by the developing ovum. In 
addition to this mode of nutrition, the ovum on each side is devouring a 
vitelline body {vt.). 
Fig. 15. — L. Leptoclini. An advanced bud in nearly median longitu- 
dinal section. The ganglion {ga.) is still in intimate connection with the 
vestibular diverticulum from which it has been formed. 
Fig. 16. — L. Tethyae. A horizontal section of an adult, passing through 
the ganglion {ga.), the vesicula seminalis {vs.), and the wide mouth {m.), 
opening into the vestibule («?.). In this individual the testes appear to have 
atrophied, 
