HYDROZOA CTENOPHORA. 
529 
medusce : compound Hydrozoa, the zooids of which are included in hydro- 
thecno, but, instead of being constructed like hydranths, are formed on the 
plan of a Medma^ a circular canal surrounding the terminal orifice, below 
the tentacular crown, and four symmetrically disposed canals running 
longitudinally backwards in the body. No manubrium, velum, lithocysts, 
ocelli, or reproductive organs were detected. Shores of Southern 
France ; its chitinous tubes are imbedded in a horny sponge, which lives 
attached to the ground at a slight depth below the surface of the sea. 
Diplophysa, Ggbr. (= Erscea^ Will. ?), of which two forms are distin- 
guished, is, according to Claus (5 & 6), the monogastric or Eudoxia-^i^ie 
of Monophyes, a new genus of Diphyidm^ with a single medusiform 
nectocalyx, in the funnel-shaped lateral channel of which the axis, with 
its polymorphic zooids, is more or less concealed. Of Monophyes, two 
species, gracilis and irregularis, are distinguished ; similar or identical 
forms have however been described by Pagenstecher and Huxley (Sphee- 
ronectes Iccellikeri). The identity of structure of the urticating organs 
and the polypites in Diplop>hysa and Monophyes, leaves no doubt of their 
genetic connection. Diplophysa therefore cannot, as suggested by 
Metschnikolf (11), be the Eudoxia-BisXct of Praya. Interesting observa- 
tions on amoeboid actions of ectodermal and endodermal cells in Siphono- 
phora are given. 
Fossil Medusjj, Graptolites, &c. 
Of two new fossil jellyfishes from the lithographic slate at Pappenheim, 
described by Hackel (10), Hexarliizites (g. n ) insignis, is the type of a 
new family of Bhizostomece, distinguished by the presence of 6 “ anti- 
mera,” all other known Rhizostomece being tetrameral. Semeeostomites 
(g. n.) zittelli belongs to the higher Medusae, with a single open mouth, 
but its position could not be fixed more precisely. 
W. Dames, Beitrag zur Kenntniss der Gattung Dictyonema, Hall (Z. 
geol. Ges. xxv. pp. 383-387, pi. xii. figs. 5-8 ; abst., Z. ges. Naturw. 2, 
xliii. p. 261), confirms the reference of Dictyonema to the Graptolites. 
Hopkinson : The Graptolites of the Arenig rocks of St. David’s, South 
Wales (abstr., P. Liverp. Geol. Soc. 1872-1873, p. 36). J. & J. 
Young: On Palceocoryne and other polyzoal appendages (J. G. Soc. 
1874, pp. 684-687, pis. xlii. & xliii.) ; the authors attempt to show that 
Pala’ocoryne is only oue type of the processes of many kinds which were 
given off by several paljeozoic Polyzoa. 
CTENOPHORA. 
A. Agashfz. Kriibryology of tho Ctenophonv. Mom. Am. Ac. x. 
pp. 355-308, pis. i.-v. ; abstr.. Am. J. Sci. (3) viii. pp. 471-176. 
A full account is given of the evolution of Tdyia roseola, a more 
abridged one of that of Pleurohrachia rhododactyla, and a short exposition 
of the differences met with in Mertensia omnn and Bolina alata. The 
evolution of the latter more aberrant genus comes nearest to the idea of 
1874. [vOL. XI.] M M 
