Grayson.] 262 [June 7, 



obtained by Col. Grayson at the Tres Marias Islands and the Island 

 of Socorro. 



With the other papers sent me by Prof. Henry, are the narratives 

 of Col. Grayson's visits to these Islands, which I have permission to 

 print with the lists of birds. Little is known or published concerning 

 these Islands, and as they are seldom visited by persons of intelli- 

 gence, the information given by so accurate an observer as Col. 

 Grayson will be found not only entertaining but instructive. Besides 

 ordinary incidents, observations of the physical features of the Is- 

 lands, interspersed with remarks upon their natural history, are re- 

 lated in a very attractive and pleasing style. 



Col. Grayson made three voyages to the Tres Marias, in 1865, 

 1866 and 1867, and visited Socorro twice, the last time in 1867. 



In April, 1869, Col. Grayson made a voyage to the Isabel Islands 

 for the purpose of studying their natural history, but unfortunately 

 while there he contracted a fever, which terminated his useful life in 

 August, after an illness of about three months. 



An interesting account of the principal incidents of Col. Grayson's 

 life is given in the Overland Monthly of Feb., 1870. 



In making the exploration of these Islands to ascertain their nat- 

 ural history, Col. Grayson was aided by contributions of funds from 

 the Smithsonian Institution and the Boston Society of Natural 

 History. 



All the material from Col. Grayson's papers is indicated by in- 

 verted commas. 



"This beautiful group of Islands, forming the subject of the present 

 article, is situated about seventy miles west of San Bias, and about 

 ninety or one hundred miles south of Mazatlan, in lat. 21l° north, 

 and long. 106i° west. They are respectively named, Maria Madre, 

 the northern and largest ; Maria Magdalena, the middle, and second 

 in size; Cleafa, the most southern, and smaller; and also San 

 Juanito, which is the smallest, lying at the northwest extremity of 

 Maria Madre. Deep and narrow passages separate them all, except 

 San Juanito, which is connected with Maria Madre by soundings of no 

 great depth. They range nearly southeast and northwest. With 

 the exception of the hacienda of Don Andres Somilara, to whom the 

 Island of Maria Madre has been leased by the original grantee, they 

 are entirely uninhabited. 



" This hacienda, consisting of a few rude huts for the laborers, and 

 a larger one for the Mayordomo, is situated on the east side of Maria 



