SCIENTIFIC SUMMARY. 
95 
separated ; suctorial fringes of the buccal arms dorsal and ventral, both on 
the axial and abaxial surfaces, — Genera, Leptobrachia, Thysanostoma, Masti- 
gias, Himautostoma, Phacopilus , Catostylus, Crambessa. 
The comparative anatomy and ontogeny of the Discomedusae enable us 
approximately to recognize very clearly the phylogeny of the ten families. 
The common stem-group of the whole order is formed by the Cannostome 
family Ephy ridae, with the stem-genus Ephyra ( JEphyrcea ) . From this, first of 
all, two divergent families were developed : — the Linergidae and the Pelagidae. 
The latter form the stem-group of the Semostomae, and split into the two 
families Cyaneidae and Flosculidae, from which last proceeded the TJlmaridae, 
and from these again the Toreumidae, the stem-group of all the Bhizostomae. 
The two families, Pilemidae and Versuridae, are probably divergent branches 
of the Toreumidae, while the Crambessidae have probably originated from 
the Versuridae (but perhaps also from the Pilemidae). This phylogenetic 
hypothesis is displayed by Prof. Hackel in the following genealogical 
tree : 
8. Pilemidae. 
10. Crambessidae. 
9. Versuridae. 
i 
7 
4. Cyaneidae. 
2. Linergidae. 
7. Toreumidae. 
6. TJlmaridae. 
5. Flosculidae. 
i 
j 
3. Pelagidae. 
1. Ephyridae. 
Ephyra. 
( Kosmos , October , 1880.) 
Classification of the Pennatulida. — In his report on the Pennatulida col- 
lected during the voyage of the Challenger , Prof. Kolliker proposes the fol- 
lowing new classification of those curious Polyps : 
Order PENNATULIDA. 
I. Rhachis with a bilateral arrangement of the polyps. 
A. Rhachis elongated, cylindrical. 
AA. With pinnules or leaves .... Sect. I. PENNATULEiE. 
* Pinnules well developed .... Subsect. 1. Penniformes. 
a. Zooids situated on the pinnules . Fam. 1. Pterocididae. 
Genera, Pteroeides, Herkl., Godefroyia , Koll. 
Sarcophyllum, Koll. 
