1893.] Zoology. 51 
ZOOLOGY. 
Locomotion of Limpets.—Herdman records’ several facts 
which seem to militate against the view that limpets do leave their 
resting place and return to it again. It has been shown that they can 
leave and travel some distance, but he found a specimen of Patella 
vulgata which was sticking to a cylindrical bar of iron and which had 
the shell molded to fit the surface. Now as the bar was short and free 
to move about, the probabilities are that if it once left the support it 
would never be able to return to it. In other cases he found limpets 
at the bottom of deep pits, from which it would be very difficult, if 
possible at all, for them to extricate themselves. 
Tunicate Studies.—Herdman publishes’ some notes on the 
structure of the Appendicularian, Œkopleura. This form was studied 
by serial sections, and the results, most interesting, are: The condition 
of the endostyle as a diverticulum to a great extent shut off from the 
branchial sac; the presence of a genital duct; the distribution of the 
enlarged ectoderm cells and the cuticular test; the exact course of the 
nerve cord through the posterior part of the body; and the shapes and 
positions of the alimentary and reproductive viscera. 
In the same publication’ Garstang points out that Appendicularia 
mossit (Mossia dolioides) is to be regarded as a member of the genus 
Kowalevskia of Fol, and that it in reality has not that importance 
from the phylogenetic standpoint which was attributed to it by Herd- 
man in his “ Challenger” report. 
The Skeleton and Teeth of the Australian Dugong.— 
Zoologists are indebted to Prof. G. B. Howes and Mr. J. Harrison fora 
valuable paper on the skeleton and teeth of the Australian Dugong, 
of which the following is an abstract : 
“The authors showed that the vertebral epiphyses are more fully 
developed than Albrecht has suspected, and that they appear late and 
rapidly ankylose with the centra, a feature of especial interest, in view 
of Lefévre’s alleged discovery of fully developed epiphyses in Hali- 
therium schinzii and Metaxytherium. On comparison with the Cetacea 
‘Trans. Liverpool Biol. Soe., vi, 22, 1892. 
*Trans. Liverpool Biol. Soc., vi, 40, 1892. 
3L. C., p- 57, 1892. 
