1881.] Loblogy. SII 
in Lake Como, Wyoming Territory, states that they never enter 
the stream of fresh water, preferring the alkali water of the lake. 
The change from alkali to fresh water undoubtedly hastens the 
metamorphosis into the Amblystoma form. “In two cases the 
change in external appearance was so abrupt that I would have 
been almost certain that another salamander had been substituted 
for the one in the jar, had I not had him so completely under ob- 
servation that it was impossible. The gills had assumed a stubby 
form about half the length that they were the night before, and 
the gill on the back of the body was nearly half gone; it took air 
quite often, and I removed it from the jar and placed it in a box 
‘with some lake grass around it to keep it moist. It completed 
the metamorphosis in a few days. I did not feed it any during 
this time. While it was in the jar it was well fed with flies.” Mr. 
Carlin found that the axolotl late in July and during August, 
leaves the lake in large numbers on rainy days and transform. 
“While catching Siredon, I have seen and caught a namber of 
Amblystoma in the lake, with the metamorphosis, as far as I 
could see, as complete as those we find half a mile from the lake. 
They cover the ground by thousands during a warm summer 
rain, coming from every conceivable place where they could have 
found shelter, from under rocks, boards, old ties, and out of go- 
Pher holes. I have a cat that eats them greedily,and I am told by 
a resident that the numerous skunks that live around the lake 
live principally on them.” After the first frost they completely 
disappear. 
* Systematic Postrion or BALanocLossus.—Elias Metschnikoff 
has returned to the view which he expressed twelve years ago 
with regard to the close affinity between this curious “worm” 
and the Echinoderms. The larvze of the two types are identical, 
Since the differences insisted on by A. Agassiz as regards the 
water-vascular system have been shown by Goette to be errone- 
Sus. Metschnikoff claims that the water-vascular system, which 
1S So eminently characteristic of the Echinoderms, is represented 
In Balanoglossus by the proboscis-sac, which he regards as a sin- 
Balanoglossus, and is lined by just the kind of membrane as in 
th 
derms is very similar to that of Balanoglossus. He regards the 
Sills as rudimentary water-vessels delayed in development and 
ra, with the two sub-types of Radiata and Bilateralia, the type 
of the latter group being Balanoglossus, : 
