334 SUMMARY OF CURRENT RESEARCHES RELATING TO 
the snails are eaten by the hedgehog they return to the intestine where 
their parents lived. 
5. Incertae Sedis. 
New Species of Pedalion.* — Herr K. M. Levander has found at 
Helsingfors a species of Pedalion which he believes to be distinct from 
the widely distributed P. mirum, and which he proposes to call P. fenni- 
cum. Some of the reasons for which he distinguishes it are : — (1) the 
absence of the two tentacles with fine hairs on the dorsal side of the 
hinder end ; from this he concludes that the presence of “ two stylate ap- 
pendages on the posterior dorsal surface ” is not to be considered as a 
generic character; (2) the lateral tentacles occupy a more median 
position than in P. mirum ; (3) the seta3 of the two lateral pairs of pro- 
cesses are equally developed on the dorsal and ventral surfaces, and 
there is no striking difference in the size of these processes ; (4) the un- 
paired ventral process only just projects beyond the hinder lip of the 
body. Only females have as yet been observed; they are 0*229 mm. 
long, and ordinarily carry one or two reddish eggs attached to their 
hinder end. The author states f that Dr. Hudson is of opinion that this 
species is distinct from his P. mirum. 
Moss-dwelling Cathypnidae.J — Mr. D. Bryce has some notes on the 
habits of these forms, and describes five new species, which he calls 
Distyla clara , D. agilis, D. inermis , Monostyla bifurca, and M. galeata ; 
they were all (except D. agilis ) found at Sandown, Isle of Wight ; it was 
found in Epping Forest, as was also D. inermis. 
Echinoderma. 
Development of Antedon rosacea. § — Dr. O. Seeliger treats at great 
length of the development of this Crinoid. When the sixteen-cell stage 
is reached by the unequally segmenting egg a groove appears in the 
region of the animal pole which runs parallel to the equator. The 
pressure of the small cells closes the cleavage cavity at the animal 
pole ; this is not effected at the vegetative pole till the forty- eight-cell 
stage is reached. The gastrula is formed by invagination at the vegeta- 
tive pole in such a way that the primary axis of the egg is exactly that 
of the embryo and the later larva ; the mesenchym arises from the endo- 
derm. 
The free-swimming larva has a proper nervous system, which is pro- 
visional only ; the apparatus first noted by Bury at the anterior pole is 
highly complicated; the cells that compose it are partly sensory and 
partly indifferent supporting cells ; both kinds of elements are rod-shaped. 
The inner ends of the supporting cells are blunt, while those of the 
sensory cells are continued into a fine process, which makes its way into 
the layer of nerve-fibres. This last is of some thickness, but near the 
periphery becomes suddenly thinner. It is supported by a basal mem- 
brane, which appears very early in the course of embryonic development. 
Before the cells of the apical spot become differentiated into sensory and 
* Zool. Anzeig., xv. (1892) pp. 402-4. f Op. cit., xvi. (1893) pp. 26 and 7. 
% Science Gossip, 1892, pp. 271-4 (5 figs.). 
§ Zool. Julirb. (Anat. u. Ontog.), vi. (1892) pp. 161-444 (11 pis.); Zool. Anzeig., 
xv. (1892) pp. 391-3. 
