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SIDNEY F. HARMER. 
from the ectodermic floor of the vestibule in the bud, and is 
connected with a well- developed system of peripheral nerves, 
ending in sense-cells bearing tactile hairs, situated on various 
parts of the body. The adult has no supraoesophageal 
ganglion. 
3. The excretory organ (paired) probably begins with a 
flame-cell : it is composed of a few large perforated cells, 
their walls filled with greenish-yellow granules, and it opens 
into the vestibule by an aperture (on each side) between the 
ganglion and the oesophagus. The nephridia are completely 
homologous with the head-kidneys of Trochosphere larvae. 
4. No hermaphrodite individuals were discovered in any 
species of Loxosoma or Pedicellina. Previous statements 
as to the hermaphroditism of Loxosoma are partly due to 
an erroneous interpretation of the ganglion as the testes. It 
is by no means improbable, however, that the same individual 
develops ovaries and testes at different seasons. Schmidt's 
accounts of the generative organs are not correct. 
5. In L. Leptoclini and in P. echinata the ova are small, 
and the embryo is supplied with nutriment from the glandular 
epithelium of the brood-pouch. In L. Tethyse this is not 
the case, but the ovum is large, and during maturation 
devours various cells which play the part of a vitellarium. 
6. After the formation of the gastrula the blastopore pro- 
bably remains in the position of the anus, a stomadaeum being 
formed anteriorly. The mesoblast arises mainly from two 
pole-cells situated at the sides of the blastopore. 
7. The ff dorsal organ” is not hypoblastic in origin; it is 
formed first as a thickening, and then as an unpaired invagi- 
nation of epiblast. The invagination closes, a layer of fibres 
is formed on its deep side, and a pair of large eyes with well- 
developed lenses appears on the organ. The “ dorsal organ” 
is not a budding structure, but is the supra-oesophageal 
ganglion. 
8. Between mouth and anus is formed a pair of invagina- 
tions of epiblast, their cavities soon fusing medianly. These, 
the “ vestibular invaginations,” remain permanently open, 
