4 GoeL 
CCELENTEKATA, 
umbral wall of the central stomach), with centripetal growth. Umbrella 
depressed, generally disk-shaped. Phylogenetic type, Ephrycea ; onto- 
genetic larval form, Ephyrula : both permanent in Ephyra. The grade 
contains the order Discomedusce alone, which is divided into the sub- 
^ order Cannostomoi (with the mouth a simple opening at the end of rudi- 
^ montary manubrium), Semoatomcc and IthizostomcG (the mouth provided 
with four or eight arm-like processes ; in the latter group, these fuse 
^ together forming secondary mouths). Peromedusce are entirely new 
forms, and most of the Stauromedusm also, the forms in both groups 
being of remarkable interest. Haeckel diagnoses 39 new genera for 63 
species, of which 51 are new ; of these, 31 genera are formed for 42 
sj)ecies, which are entirely new. In all, 79 new species are described. 
24. Hartog, M. M. On the Mode in which Hydra swallows its prey. 
Q. J. Micr. Sci. xx. pp. 243 & 244. 
The nematocysts found in the endoderm appear to have been swallowed 
with the prey, and to be undergoing digestion. Interstitial cells in 
isolated patches are found in the tentacles. 
25. Hertwig, O. & R. Der Organismus der Medusen und seine Stel- 
lung zur Keimblattertheorie. Denk. Ges. Jena, ii. pp. 1-70, 3 pis. 
26. Hertwig, R. Ueber den Bau der Ctenophoren. Jen. Z. Nat. xiv, 
pp. 313-457, 7 pis. 
The author deals with the histology of the group. With regard to the 
structure of the generative organs, Hertwig differs from Chun, and agrees 
with Claus as to their ectodermal origin. The nervous system consists of 
two portions — a ganglionic plexus equally distributed below the epithe- 
lium (ectodermal), and a system of fibres passing separately into the gela- 
tinous layer (mesodermal); these, no doubt, are connected with the 
ganglionic plexus, but the author has been unable to demonstrate the 
connexion. The arrangement of the nervous and muscular fibres leads 
the author to separate the Ctenophora from the Ilydrozoa and Anthozoa^ 
and regard them as derived from very primitive ancestors, when very 
few characteristics of Cculenterata were present. 
27. Hincks, T. On new Hydroida and Polyzoa from Barents Sea. 
Ann. N. H. (5) vi. pp. 277-286, pi. 
28. Kerschner, L. Zur Entwickelungsgeschichte von Hydra. Zool. 
Anz. iii. pp. 454 & 455. 
A preliminary communi(;ation. 
29. Klipstein, a. von. Die Tertiarablagerungen von Waldvockelheim 
und ihre Poly pari enfauna. JB. geol. Reichsanst. 1879, pp. 61-68. 
30. Korotneff, a. Ueber seine anatomischen, biologischen und embryo- 
logischen Beobachtungen au Hydra. (Verb. Zool. Sect. vi. Ver- 
sammlung Russ. Naturf.) Zool. Anz. iii. pp. 165-167. 
Besides describing the formation of the egg and its further develop- 
ment, the author remarks upon the columnar shape of the ectoderm cells 
in the basal portion of the body, and notes the presence of a mucous 
