118 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Cyrenidse. The byssal gland is much reduced, the inner gills alone 
function as brood-pouches ; digestion is thought to be a continuous pro- 
cess, and it has seemed worth while to put on record that “ the regular 
three pairs of Lamellibranch ganglia are present.” 
Bryozoa. 
Notes on Cyclostoma.* — Mr. S. F. Harmer is able to confirm the 
normal occurrences of embryonic fission in these forms by an account of 
Idmonea serpens , the ovicell of which is shown to be a modified zooecium. 
Dealing next with the lately expressed view of Dr. J. W. Gregory 
that there are no true genera among Cyclostoma, Mr. Harmer urges that 
that naturalist has not sufficiently noticed the ovicells, the value of 
which in classification has been urged by Mr. Waters and himself. 
Dealing with various recent species the author shows that they may be 
distinguished by means of their ovicells, and he expresses the opinion 
that it is possible to draw precise diagnoses of recent Cyclostomatous 
genera. There is probably a law of growth common to all recent 
species. 
Eschara lapidescens van Baster.j* — Mr. R. T. Maitland discusses 
this calcareous zoarium from the brackish water of Zeeland. It seems — 
so far as we understand the paper — to be a form of Membranipora ; but 
the author points out that neither Lamarck, nor Johnston, nor Hincks, 
nor P. J. van Beneden have taken knowledge of van Baster’s observa- 
tions (1759). 
Arthropoda. 
Tegumentary Innervation in Arthropods.^ — Herr E. Holmgren re- 
fers to his work (published in Swedish §) on the integument of cater- 
pillars. The larger nerves show an arborescent branching, the smaller are 
dichotomous. The fine twigs end partly in bipolar sensory nerve-cells, 
the unbranched terminal process of which runs out into a hair or passes 
between two epidermic cells up to the cuticle. In caterpillars there 
seems to be no trace of a ganglionic grouping of nerve-cells such as is 
often seen in Crustaceans ; and another difference is that the nerve-cells 
in caterpillars are much more superficial. Most of the hairs on the 
body are provided with sensory nerve-cells ; they are at once glandular 
and sensitive. Sometimes, as Rina Monti has also shown, the nerve-cells 
in the skin of insects are multipolar, and a plexus arrangement, as in 
Ctenophora, is sometimes demonstrable. Like Retzius and vom Rath, 
the author has found only bipolar sensory nerve-cells in the Crustacean 
skin. Ramified connective and pigment-cells may be seen sending 
processes into the hairs. Perhaps the multipolar nerve-cells described 
in Astacus by Bethe are really connective. 
a. Insecta. 
Larvae of British Butterflies and Moths.|| — Mr. G. T. Porritt con- 
tinues the editing of the late William Buckle’s work ; this, tho seventh, 
* Proc. Cambridge Phil. Soc., ix. (1897) pp. 208-14. 
t Tijdschr. Nederland. Dierk. Ver., v. (1896) pp. 10-14. 
X Anat. Anzeig., xii. (1896) pp. 449-57 (7 figs.). 
§ K. Svensk. Vetenskaps-Akad. ITandl., xxvii. (1895) No. 4. 
|| London, printed for the Ray Society, 1897, xv. and 176 pp., pis. cvi.-cxxvii. 
