HYDROZOA AND CTENOPHORA. 
GceL 7 
all the true free-swimming Medusce, and probably numerous fixed Medusce ; 
to the former, in respect of their ova, a large number of forms, but in 
respect of both products, the author only recognizes at present the genus 
Plumularia. Making a special study of this genus and of the Sertulariidce 
and CampanulariidcB, the author shows that sexual cells do take origin in 
the coenosarc ; that this is a normal mode of origin of considerable im- 
portance, and at any rate in the case of the female products, widespread 
occurrence ; and that such coeuosarcal cells afterwards migrate to the 
gonophores. 
51. . Ueber eigenthumliche Organe bei Eudendrium racemosurriy 
Cuv. MT. z. Stat. Neap. iii. pp. 1-14, 1 pi. 
Certain peculiar organs, processes of the body wall, comprising both its 
layers, are found below the hydranths. They are muscular, and possess 
a very large number of nematocysts ; they are probably special organs of 
defence, comparable to the nematophores of PlurnulariidcB, 
52. Taramelli, T. Scoperta di Graptoliti nella Carina. Bull. Com. 
Gool. Ital. 1881, p. 3G0. 
Evidently Graptolites monograptua. 
New genera and sjjecies : — 
Sub-Class HYDROMEDUS^. 
Order i._, Gymnoblastea-Anthomedus2B. 
Thamnostylus dinema, Haeckel, 1879, System der Medusen, p. 85, No. 95, 
and (24) pp. 2-5, pi. i. 
. Mahella, g. n. Resembles Dysmorphosa very closely, with the excep- 
tion that it has eight radial chymiferous tubes ; for M. gracilis, sp. n. ; 
Fewkes, (16) p. 146, pi. vi. figs. 2 & 3, Narragansett Bay. May be the 
same as D.fulgurans, A. Ag. 
Modeeria, g. n., for if. multitentacula ; Fewkes, (16) p. 149, pi. iii. 
figs. 7-9, Buzzard’s Bay, A. Ag. 
Dinematella, g. n. Allied to Stomatoca, iov D. cavosa\ Fewkes, (16) 
p. 151, pi ii. figs. 2 & 3, and pi. iv. fig. 3, Laboratory Cove, Newport, R.I. 
Eiutima gracilis, sp. n., Fewkes, (16) p. 158, pi. v. figs. 1-4, Newport. 
May be the adult of E. mira, variabilis, or limpida. 
Order ii., CALYPTOBLASTEA-LEPTOMEDUSiE. 
PtycJiogena pinnulata, Haeckel, 1879, 1. c. p. 148, No. 150, and (24) 
pp. 7-9, pi. ii. 
Filellum bouvieri, sp. n., Jullien, (30) p. 291, with fig., Cape Verde 
Islands. Allied to E. serpens, Hassell. 
Fewkes (14) describes the following : — 
Lafoea elegans, sp. n., p. 129, Barbados, 180 fath. and 120 fath. Differs 
from L. fruticosa in having pinnately arranged ultimate branches. Closely 
resembles L. helicioides, All., but larger. 
