744 THE AMERICAN NATURALIST. - (VoL. XXXII: 
are of special interest. According to this observer, Ornithorhynchus 
digs a burrow whose mouth lies below water level on the steep bank 
of a stream, and whose zigzag course leads to an enlarged nesting 
chamber at a level above high-water mark. The nest chamber is 
said to be as large as a platter and as high as a loaf of bread. The 
nest is lined with hair taken from the backs of the male and the 
female. On one occasion a nest was found with two eggs in it, both 
of which were unfortunately broken. At another time a female was 
observed suckling her two young. The female had no nipples. She 
lay on her back, and her young tapped with their bills about the 
small sieve-like openings of the mammary glands. The milk ran 
from these into a median groove on the skin formed by the longitu- 
dinal musculature, and from this groove the milk was taken by the 
young. The young remain in the nest till they attain a size of twelve 
centimeters, and when twenty centimeters in size they venture with 
the mother on the water. GHP 
New Goby from Clipperton Island. — In the Proceedings of the 
New England Zoélogical Club for June 9, 1899, Vol. I, p. 63, Mr. 
Samuel Garman describes a new goby from Clipperton Island, off 
the west coast of Mexico, as Gobius arundelit, In the rather minute 
subdivision of genera adopted by Jordan and Evermann this species 
is probably referable to Aboma. DSi 
The Chelæ of the Lobster. — The forms of the chelæ in lobsters 
have been reinvestigated by Stahr.! In the great majority of cases 
the European as well as the American lobster possesses two chelz of 
typically different shapes. One is thin-walled, delicate, and pro- 
vided with small teeth. The other is swollen and large, and has its 
biting surfaces covered with an irregular double row of knob-like 
eminences. The occurrence of these two forms of chelz is not cor- 
related with sexual differences or sides of the body. In the Ameri- 
can form animals with both chelz of the delicate type are of rare 
occurrence, but this condition is not so uncommon among the Euro- 
pean lobsters. The delicate type of chelæ possesses teeth of four 
sizes arranged in eight-place intervals, and it may also carry an 
additional tooth not unlike those found on the heavier type of chela. 
Although the representatives of these two types are as a rule easily 
1Stahr, H. Neue Beiträge zur Morphologie der Hummerschere mit physio- 
logischen und a Bemerkungen, /enaische Zeitschrift, Bd. xxxii, 
Pp- 457-482, Taf. xx-xxi, I 
