No. 1. — (Lerrer No. 1.) Zo C. P. PATTERSON, Superintendent Coast 
Survey, Washington, D. C., Jrom ALEXANDER AGASSIZ, on the 
Dredying Operations of the United States Coast Survey, Steamer 
“Blake,” during parts of January and February, ۰ 
Since I joined the ship at Havana, during the last part of December, 
1877, not only have our operations been greatly retarded by continued 
bad weather, but also by the unfortunate grounding of the “ Blake” 
at Bahia Honda while in charge of a Spanish pilot. Nearly three weeks 
were lost before the ship could be floated and again in condition to re- 
sume work, Notwithstanding these delays, the following lines have 
been run thus far ;— 
l. One line from Havana to Sand Key in depths of from 320 fathoms to 951 
fathoms. 
2. A second line on the coast of Cuba from Havana to a short distance west 
of Bahia Honda, from 292 fathoms to 850 fathoms, 
3, A short line of about 40 miles northerly from the Tortugas, from 111 
fathoms to 37 fathoms, to examine the character of the Fauna of the Florida 
Bank to the westward of the mainland as far as the 100-fathom curve, 
4, A line from the 100-fathom curve on the west side of the Florida Bank 
about 30 miles north of the Tortugas, across to the 100-fathom curve on the 
northeastern side of the Yucatan Bank, from 110 fathoms to 1,920 fathoms to 
95 fathoms, 
5. A line from 1,568 fathoms north of the Alacran Reef, from the deep 
basin extending from the northern slope of the Yucatan Bank toward Vera Cruz 
up to 84 fathoms on the northern edge of the Yucatan Bank. 
6. A line from the 100-fathom curve on the north side of the Yucatan Bank 
to Alacran Reef, then in a southeast direction from there into 20 fathoms off 
the Joblos Islands diagonally across the Yucatan Bank, 
7. A line in the trough of the Gulf Stream from north of Cape San Antonio 
to Sand Key, Florida, from 1,323 fathoms to 339 fathoms. 
In all, about 1,100 miles of lines, taking the shortest distances from 
point to point. 
The Fauna of the Yucatan Bank is identical with that of the Florida 
Bank, being characterized by the same species of Echinoderms, Mol- 
lusks, Crustaceans, Corals, and Fishes, so well known already from 
shallow water on the Florida side. While on the Yucatan Bank I had 
the chance of examining the great Alacran Reef, an excellent plan of which 
is given on one of the British Hydrographic maps of the Gulf of Mexico. 
It is one of the circular reofs resembling atols, and I was the more desir 
