1890.] Zoology. a 3m 
the spines are not the prime agents in the excavating process, they aid 
the teeth by their rotary motion. It has been surmised by some that 
marine alge, by their chemical action upon limestone, aid the urchins 
in the boring of their holes, but it cannot be found that alge exert any 
such chemical influence, and urchins bore into sandstones, granite and 
lava as well as into limestones, so that there is no relation between 
alge and urchin-holes. The principal object of the toothed urchins in 
thus excaVating seems to be to find shelter from the violence of the 
waves. (See Fewkes, NATURALIST, Jan., 1890). 
Mollusca : Annelida.—The Polyzoa collected in Japan by Dr. L. 
Döderlein are described in the Archiv fir Naturgeschichte, of Decem” 
ber, 1889, by Dr. A. Ortman, and the memoir is illustrated by four 
double plates. 
Nos. 5 and 6 of the Annals of Natural Sciences (Zoöl., Vol. VII.), 
are occupied by M. Louis Roule’s studies upon the development of the 
Annelida, and especially of Euchytroedes marioni, a new species of 
limicolous oligochoete. His results are somewhat startling, inasmuch as 
they induce him to place the mollusks and the annelids in the same 
group, called by him Trochozoaires. In both groups the ccelom is not 
a true enteroccele, since it is not derived from the archenteric diver- 
ticular, but ‘is hollowed out, without direct relation with the archen- 
teron, in the mass of cells that are produced by the initial mesoblastic 
segmentation. Moreover, both groups, as is sufficiently well-known, 
have similar larvae, Trochospheres or Trochozoa. The chief difference 
is the polymerism of the one group and the monomerism of the other. 
An immense squid, the long arms of which, although shrunk, 
measured 30 feet in length, and the body and short arms of which 
were 60 feet in circumference, was stranded in November last upon 
Achill Island, off the west coast of Mayo, Ireland. Some of the short 
arms measured four feet in circumference. 
Arthropoda.—lIn the first and second numbers of the Annals and 
Magazine of Natural History, for 1889, M. E. L. Bouvier describes the 
nervous system of decapodous crustaceans, and the relations of that 
system to the circulatory system, giving particular attention to the 
Anomoura. The Caridide have an abdominal chain of six pairs of 
ganglia. In the Palinuride these pairs are completely fused trans- 
versely, but in the Astacide are less so. In the Galatheidz there are. 
still the same number of abdominal ganglia, but they are more concen- 
trated longitudinally, and less so transversely. In the Paguride the 
longitudinal concentration increases, while the transverse union is 
