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SUMMARY OF CURRENT RESEARCHES RELATING TO 
So-called Palolo-Worm.* * * § — Dr. B. Friedlsender has given much at- 
tention to the puzzling phenomenon of shoals of “ Palolo ” at Samoa. 
As is well known / they appear in immense numbers at regular intervals 
with astounding punctuality, even to the hour. The water is thick 
with wriggling headless worms, “ thick as vermicelli soup/’ as Agassiz 
said. It can hardly be doubted that they come from the coral reef, and 
that they are the liberated posterior ends of worms modified in connec- 
tion with reproduction. As the author notes, Dr. G. Thilenius has also 
and independently discovered the Palolo worms on the reefs, and inter- 
preted the swimming portions as reproductive bodies. The riddle 
remains, however, that they appear in constant relation to the phases 
of the moon, on the day of the last quarter. 
Incubation of the Skate-Leech.t — There is a note in the Journal 
of the Marine Biological Association on the parental care exhibited by 
Pontobdella muricata L. A specimen was dredged along with a scallop- 
shell, and was seen to be mounting guard over a group of eggs. It 
continued to do so in the aquarium for at least 123 days. “ For what 
purpose the skate-leech remains with its eggs during incubation appears 
uncertain. . . One may presume that their protection is the chief object, 
whether from active enemies or from the mere accumulation of sand, &c., 
is doubtful. . . . Hatching is accomplished by the perforation of the 
membrane of one of the fenestne. The chitinous part of the shell is 
not ruptured in any way.” 
Urns of Sipunculus.J — MM. J. Kunstler and A. Gruvel have been 
able to cultivate these remarkable bodies for prolonged periods, and 
have followed with precision the successive changes by which they pass 
from relative simplicity to unexpected complexity of structure. 
Rotatoria. 
Fauna of the Nurmijarvi Lake.§ — Mr. K. E. Stenroos has studied 
by the side of this inland lake of Finland the fauna of its waters. After 
describing the lake itself and its surroundings, he gives a particular 
account of the Rotifera, which are represented therein by 157 sj)ecies. 
Unfortunately the author has not been able to abstain from describing 
a number of species as new upon the most slender variations from the 
published figures and accounts. Twenty-six new species are named, 
about one-half of which are almost certainly “ old friends,” and a num- 
ber of the remainder so ill defined that it will be very difficult to 
recognise them again. The following are the new names : — Limnias 
nymphsese, Pseudoecistes rotifer (this is the variety of CE. nelatus figured 
in Dr. Collin’s note-book with two eyes near the edge of the corona), 
Conochilus limneticus ( = C. unicornis ), Microcodides abbreviatus (= M. 
robustus ), Notops fennicus (= N. minor f Notommata monostylseformis 
( = Monostyla bifurca'), Proales mirabilis , Furcularia trihamata ( = F. 
forficula), F. macrodactyla (probably = Diaschiza semiaperta ), Monom- 
* Biol. Centralbl., xviii. (1898) pp. 337-57. 
t Journ. Mar. Biol. Ass., v. (1898) pp. 195-6. 
X Comptes Rendus, cxxvi. (1898) pp. 970-2. Cf. this Journal, 1897, p. 126. 
§ Acta Soc. pro Fauna et Flora Fenuica, xvii. 1, Helsingfors, 1898, pp. 1-177 
(3; P ls.). 
