508 Walks Round San Francisco—The Bay Shore. [ August, 
sea-water, many individuals of a singular fish belonging to the 
family Batrachide or toad-fishes. If we attempt to catch it, it will 
salute us, if we are not careful, by thrusting into our hands the 
sharp spines with which its gill-covers are armed, at the same 
time emitting a most characteristic grunt, which though not very 
loud is rather alarming to one unacquainted with the fish, and 
usually causes him, in conjunction with the wound from the 
spines, to drop it zzstanter. A glance at the under side of the 
rock which once roofed in her abode, will show us, covered as it 
is with ova about the size of a pea, that she comes to the shore 
to spawn, This fish, Porichthys notatus as it was named by 
Girard, is sufficiently ugly when looked at above, but its under 
side sparkles with rows of shining pores, emitting the mucus 
which covers its body and renders it as slippery as an eel. 
Under every loose rock we turn over there is a colony of a pale 
greenish little crab, with a square carapax and whitish pincers 
which are uplifted menacingly at the unwelcome intruders as 
their owners scuttle off to hide themselves under the nearest 
shelter. This species, Heterograpsus oregonensis Dana, is com- 
monest at this point, but it is often accompanied by the almost 
equally common and much prettier Heterograpsus nudus Dana, 
which attains larger dimensions, and has a carapax and legs 
beautifully marbled with red and purple brown. The first species 
is extremely abundant in the brackish creeks which permeate the 
marshes round the bay. 
In the crevices of the larger rocks, up to quite high-water mark, 
another square crab, dark-green in color, and with the last joints 
of its four pairs of walking feet armed with spinules, by which it 
holds tightly to the slippery surface, may be found in consider- 
able numbers, but it is rather difficult to secure entire, not only 
from the difficulty of reaching it in its hiding places, but from the 
extreme readiness with which it throws off some of its limbs 
when escape proves impossible. This is Pachygrapsus crassipes 
andall. Farther on still, where the loose rocks are larger, the 
large Cancer magister Dana, the species usually eaten by the prac- 
tical carcinologists of San Francisco, is occasionally found, having 
_ presumably retired from the deeper water to shed his plate-armor 
ie _ in peace. But it is too early in the season for him, and we 
~ encounter nothing new until, between two rocks, we see an eight- 
wee pni crawling along, the arms united by a membrane, sO 
