18 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
to this market. His excellent training as a naturalist and knowledge of ichthyology 
enabled him to study critically the fishes found and to gather a large amount of 
interesting and important information concerning them. He has very kindly furnished 
us a report embracing the results of his observations and inquiries, and we desire in 
this place to express to him our deep appreciation of his intelligent interest in this 
matter and our thanks for the valuable information we have thus obtained. This 
information will be found in the chapter dealing with the commercial fishes. 
Caguas. — While at San Juan a trip was made toCaguas, on the military road, 25 
miles (36 kilometers) south from San Juan and near the center of the island from 
north to south. This place has an elevation of 2J6 feet above sea-level, and lies in a 
beautiful valley surrounded by hills of moderate height. The Rio Caguitas Hows 
northward just west of the town, then turns eastward and, after a tortuous course of 
about 2 miles, flows into the Rio Loiza, near the hacienda of Senor Nicolas Quinones. 
The seining of this stream was quite satisfactory. Though fishes of considerable 
size were rare, young fishes were fairly abundant, the following species being repre- 
sented: Awaous taiasica , Agonostomus monticolci , and Sicydium caguitce. A small 
shrimp (Bithynis olfersii) was very abundant, especially among weeds growing in 
the Avater’s edge, where the bottom was somewhat muddy. A much larger shrimp, 
possibly the same species, and a sword shrimp were found in some numbers. Only a 
single species of water plant, probably Myriophyllum , was found in a feAV places. 
The Rio Loiza was examined just above the mouth of the Rio Caguitas, 2 miles 
northeast of Caguas, where it is 75 to 100 feet wide and 1 to 7 feet deep. One shore 
is usually low, while the other may be high, rising abruptly into wooded hills. At 
the hacienda is a ford, and both shores are low. Seining was not very satisfactory. 
A great many young of the u dajao” ( Agonostomus monticolci ) were caught, and a 
few small gobies were seen. We were told that good-sized examples of “dajao” and 
“guavina” occur here, and eels are caught in the “nasa,” as explained elsewhere. 
The same crustaceans and moilusks were found here as in the Rio Caguitas. 
Bay avion River. — One visit was made to the town of Bayamon, about 6 miles south 
of San Juan, and the Bayamon Ri ver examined near the town, where it is a stream of 
some size, flowing through a level plain and with red clay banks 2 to 10 feet high. 
The water was roil)’ from recent rains and somewhat above low-water stage. The 
river contained considerable aquatic vegetation. At first the seine was hauled down- 
stream in the usual way over the riffles, through the deep holes and through various 
inviting places, but scarcely anything was caught. Then it occurred to us to see if 
the fish might not be hiding in the holes under the banks. The seine wa| stretched 
lengthwise of the stream parallel with the bank and a few feet from it, and then 
pulled through the water and up against the bank. Then with sticks we prodded in 
the holes under the bank to scare out anj^ fishes that might be hiding there, and on 
lifting the seine Ave found it usually well filled with moron, guavina, ciaga, dajao, 
anguilla, camaron, etc. Similar experience was had at Caguas in the Rio Caguitas 
and the Rio Loiza. Evidently the fresh-water fishes and crustaceans of these rivers 
have been able to protect themselves from being carried out to sea during high water 
by occupying protected places in the banks, and this has now become a habit with 
them. This habit is discussed at length in another portion of this report. 
Arecibo. — The Fish Hawk did not make any stop at Arecibo, but Professor Ever- 
mann and Mr. Wilcox visited it by rail from San Juan. Considerable commercial 
