78 JOHNS HOPKINS UNIVERSITY MORPHOLOGICAL MONOGRAPHS. 
each cell of the endothelium of the ampulla and of the pedalia (Figs. 
7, 17); the peculiar nuclei in the endothelial cells of the ampulla 
(Fig. 20); the longitudinal muscles of the tentacles being completely 
inclosed within canals of the supporting lamella, but near the base 
of a tentacle becoming subectodermal. This demonstrates their 
ectodermal origin. In Tripedalia it is seldom that any of these 
muscles become enclosed as in Charybdea (Fig. 29). 
If to the reader my results seem to embody a somewhat hetero- 
geneous detail, he must remember that the work consists partly 
in corroborating and partly in supplementing the work of previous 
observers, and that, in general, histological detail does not usually 
make the most readable paper. 
BroLoGicaAL LABORATORY, 
Jouns Hopkins Untv., May, 1899. 
LITERATURE. 
LITERATURE REFERRED TO IN THE SECTION ON PHYSIOLOGY. 
I. Romanes, G. J. a. °75,°77. The Locomotor System of Medusee. Philosoph- 
ical Transactions. London. Vol. CLXVI, pt.1. Vol. CLXVII, pt. 2. 
b. °85. Jelly-fish, Star-fish and Sea-urchins. London. 
II. Mursacu, Louts. °95. Preliminary Notes on the Life-history of Gonione- 
mus. Journal of Morphology. Vol. XI. 
Ill. Hesse, R. °95. Uber das Nervensystem und die Sinnesorgane v. Rhiz- 
ostoma Cuvieri. Zeit. Wis. Zool., B. LX. 
IV. Ermer, TH. Zoologische Untersuchungen. °74. Wiirzburg Verhandlungen. 
VI. Bad. . 
V. Harcket, E. °79. Monographie der Medusen. Jena. 
VI. Beraer, EK. W. ’°98. Abstract of Dr. F. 8, Conant’s Notes on the Physi- 
ology of the Medusxe. Johns Hopkins University Circulars. Vol. XVIII, No. 137. 
VII. (See also 8, below.) 
LITERATURE REFERRED TO IN THE SECTION ON HISTOLOGY. 
1. Carribre, J. °85. Die Schorgane der Thiere. Miinchen u. Leipzig. 
2. Haake, W. ’87. Scyphomedusen des St. Vincent Golfes. Jen. Zeit. f. 
Naturwis., Bd. XX., pp. 596-597, 602-604. 
3. Cnaus, ©. °78. Uber Charybdea marsupialis. Arb. aus dem Zool., Inst. 
Univers. Wien., Bd. I. 
4, SCHEWIAKOFF, W. °89. Beitrage zur Kenntniss des Acalephenauges. Morph. 
Jahrb., Bd. XV, H. 1. 
5. Parren, WILLIAM. a. ’89. Studies on the eyes of Arthropods. II. Eyes of 
Acilius. Journal of Morphology. Vol. II. 
b. ’98. A Basis for a Theory of Color Vision. American Naturalist. Vol. 
XXXII, No. 383. 
