30 SCIENCE SKETCHES. 
Pacilichthys is a chubby little fish, as compared 
with the other darters. In its movements it is 
awkward and ungraceful, though swift and savage 
asa pike. One of the mildest of its tricks which 
we have noticed, is this. It would gently put its 
head over a stone and catch a water-boatman by 
one of its swimming legs, release it, catch it again 
and again release it, until at last the boatman, evi- 
dently much annoyed, swam away out of its reach. 
It will follow to the surface of the water a piece of 
meat suspended by a string. It is more alert in 
discovering this than a hungry sunfish or rock- 
bass, and it can be led around like a pet lamb 
by a thread to which is fastened a section of a 
worm. 
A more beautiful fish than this — beyond ques- 
tion the handsomest of them all—is the Blue- 
breasted Darter (Mothonotus camurus Cope). It is 
a deep olive-green little fish, sprinkled over with 
dots of carmine like a brook trout. Its breast is ofa 
deep ultramarine blue, and its fins gayly variegated 
with blue, yellow, and crimson. But we hardly 
learned to know it as an aquarium acquaintance; 
for we found it but twice, both times in the clearest 
of water, and our specimens never survived con- 
finement more than two or three hours. We can 
only say of their habits that they died where other 
darters lived, and that before they died all other 
fishes seemed cheap and common beside them. 
The darter of darters is the Fan-tail (Etheostoma 
Jiabellare Rafinesque). Hardiest, wiriest, wariest 
of them all, it is the one which is most expert in 
catching other creatures, and the one which most 
