78 JOHNS HOPKINS UNIVERSITY MOEPHOLOGICAL 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 Chary bdea (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. 



BIOLOGICAL LABORATORY, 



JOHNS HOPKINS UNIV., May, 1899. 



LITERATURE. 



LITERATURE REFERRED TO IN THE SECTION ON PHYSIOLOGY. 



I. ROMANES, G. J. a. '75, '77. The Locomotor System of Medusae. Philosoph- 

 ical Transactions. London. Vol. CLXVI, pt. 1. Vol. CLXVII, pt. 2. 



b. '85. Jelly-fish, Star-fish and Sea-urchins. London. 



II. MURBACH, Louis. '95. Preliminary Notes on the Life-history of Gonione- 

 mus. Journal of Morphology. Vol. XI. 



III. HESSE, R. '95. Uber das Nervensystem und die Sinnesorgane v. Rhiz- 

 ostoma Cuvieri. Zeit. Wis. Zool., B. LX. 



IV. EIMER, TH. Zoologische Untersuchungen. '74. Wiirzburg Verhandlungen. 

 VI. Bd. 



V. HAECKEL, E. '79. Monographic der Medusen. Jena. 



VI. BERGER, E. W. '98. Abstract of Dr. F. S. Conant's Notes on the Physi- 

 ology of the Medusa?. Johns Hopkins University Circulars. Vol. XVIII, No. 137. 



VII. (See also 8, below.) 



LITERATURE REFERRED TO IN THE SECTION ON HISTOLOGY. 



1. CARRIERE, 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. GLAUS, C. '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. PATTEN, 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. 



