28 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
The Hydroid medusa Obelia lucifera was very plentiful throughout 
June; on adding a saturated solution of corrosive sublimate to the sea- 
water containing them the animals were stimulated to phosphorescence, 
and the position of each medusa was indicated by a small clear ring of 
blue light round the margin of the umbrella. There was an abundance, 
on July 4th, of the young of the Tunicate Oikopleura lophocerca. On the 
same day there was a great increase in the number of Dinoflagellates, 
and oceanic Radiolaria of Haeckel’s group Acantharia were also found. 
It seems that the surface-layers of the sea are, with their plankton, dis- 
placed through considerable distances by the prolonged or powerful 
action of the wind in one direction. The interesting Archiannelid 
Protodrilus leuckarti, not hitherto recorded from any locality other than 
the Mediterranean and the Black Sea, has been found. 
Marine Invertebrate Fauna of Plymouth.* — Mr. W. Garstang has 
some notes on the collecting operations undertaken by the Marine 
Biological Laboratory in 1892. The rare Leucosolenia lacunosa was 
dredged in 25 fms. ; this calcareous sponge was attached by its 
slender stalk to an old egg-case of Scyllium canicula , which was itself 
adhering to the stem of a Gorgonid. Tubiclava cornucopise, first dredged 
in the Shetlands, is represented by a colony of 90 to 100 polypes. 
Haliclystus octoradiatus has been discovered in hundreds. Of the 
Anthozoa the Eloactis Mazeli of Jourdain is an interesting addition to 
the British fauna, and, on the whole, the Actinians of Plymouth offer 
a valuable field for special investigation. The researches of Mr. Gamble 
show that there exists a Rhabdoccele fauna unparalleled in the number 
of its species. Of Annelids the dredge is constantly bringing up species 
whose presence has been hitherto unsuspected ; Myxicola has been added 
to the list of Plymouth Annelids, and Staurocephalus rubrovittatus has 
been found on several occasions. Phoronis is quite plentiful in certain 
parts of the Sound, and its beautiful larva has been a feature of tho 
autumn tow-nettings. Crisia denticulata , a Polyzoon which Mr. Harmer 
reported to be rare at Plymouth, has been found abundantly in the 
deeper waters a few miles outside the breakwater. 
The principal additions to the Gastropod fauna have been from 
among the Opisthobranchia. Ampliorina cserulea , a species which has 
not been met with on English coasts since the time of Montagu, was 
dredged on September the 12th. Perhaps the most interesting addition 
of all has been the rediscovery of D’Orbigny’s Stiliger bellula. A 
species of Amphipod which appears to be very locally distributed, 
Unciola crenatipalma , is found plentifully on a muddy bottom at a depth 
of twenty fathoms. The male of Anthura gracilis has been found and 
confirms the prediction of Norman and Stebbing concerning the secon- 
dary sexual characters of the male of this species. Of the Schizopod 
Crustaceans, Macromysis flexuosa has been very abundant during the 
past summer, countless myriads being found close to the water’s 
edge in the estuary of the Yealm. Gastrosaccus normani , which does 
not appear to have been seen on our coasts since 1871, was taken in the 
surface net on the night of September the 21st. Among the Decapoda 
Achseus Cranchi is a valuable addition. 
* Joum. Marine Biol. Assoc., ii. (1892) pp. 333-9. 
