MEM. M. C. Z, IX. No. 3.— ACALEPHS, POLYPS. Lg 
IDUINMEID. Wie 
Development of the TRAcHYMEDUSA, continued. Young Stages of the Meduse of the Hyproma, 
and Acrasrepa. Figures from AtexaNvder AGassiz, Grorce J. Attman, J. Water 
Frewkes, Ernst Hancker, and Frivz MULuer, 
C. can.ere. Cireular canal. r. tb!. Radial tube which has not yet grown 
car. Cavity. to the circular canal. 
E. em. ta. Embryonic tentacle. T. ta. Tentacle. 
Cae. Stomach: om Chymiferous tubes. 
gm. Bud. thl. > 
H. hy th. Hydrotheca. U. ubr. Umbrella. 
L. lab. Lip. V. vel. Velum. 
Zl. rm. Lateral ramus, corbula rib. a.  Unruptured perisare at the extremity 
M. man. Manubriain. of a branch. 
mds. gm. Medusa bud. B.  Chitinous envelope ruptured, and the 
N. nt cy. Nematocyst. ceenosare protruding. 
O. oa. vs. Ovarian vesicle. ¢ The cenosare protruding more than 
ocl. Ocellus. in B. 
ocy. Otocyst. y:. Body escaped from the hiydroid. 
or. Mouth. 7. New branch. 
P. pap. Papilla. 6. Tube formed about the bud. 
Tier. tb: Radial tube. am.  Lase of attachment. 
1-2. Glossocodon ewrybia (Liriope ewrybia). From Haeckel, Beitrage zur Naturgeschichte der Hydromedusen, 
Erstes Heft. Die Familie der Russelquallen (Geryonida), Pl. III., figs. 29, 30. 
1. Young larva, with bell fully formed, seen from the oval side. The beginnings of four tentacles, which later 
form the embryonic tentacles, are seen as four small buds. vel. Velum. 
2. Larva of about the same age, seen from one side. wbr. Umbrella. 
3. From Fritz Miiller, Archiv fiir Naturgeschichte. 1859. Pl. XI., fig. 16. 
3. Still older medusa, seen from one side. The provisional tentacles are considerably developed, and from their 
tips project the tongue-like spurs. cav. Cavity of the bell. ubr. Umbrella. 
4-7. Glossocodon tenwirostris, sp. Ag. From Fewkes, Notes on Acalephs trom the Tortugas, with a Description of 
New Genera and Species. Bull. Mus. Comp. Zodl. Vol. 1X., No. 7, Pl. VIL, tigs. 2-5. 
4. Larval medusa with stiff embryonic (transitory) tentacles (em. ta.), in which the permanent tentacles are not 
developed. man. Manubrium (rudimentary in character). 7. 4b. Radial chymiferous tube. The club- 
shaped bodies are, comparatively speaking, very large. 
5. Older larva, in which the embryonic tentacles (em. ta.) have somewhat diminished in size, and a true tentacle 
(ta.) has begun to form. 
6. Older larva, where the tentacles (¢#.) haye grown much longer. The manubrium (man.) has also increased 
very greatly in size. Embryonic tentacle (em. ta.) reduced in size; almost lost. 
7. Older larva, wholly destitute of embryonic tentacles, while the true permanent tentacles (fa.) are very long, 
asin adult. man. Manubrium. +r. tb, Radial tube. wbr, Umbrella. 
