No. 4. — Reports on the Results of Dredging, under the Supervision 

 of Alexander Agassiz, in the Gulf of Mexico, and in tJie Carib- 

 bean Sea, 1877-79, and along the Atlantic Coast of tJie United 

 States during the Summer of 1880, by tJie United States Coast 

 Survey Steamer "Blake," Lieutenant-Commander C. D. Sigs- 

 bee, U. S. N., and Commander J. R Babtlett, U. S. N., Com- 

 manding. 



XVI. 



Preliminary Report on the Comatidce,* by P. Herbert Carpenter. 



The Comatula collection of the Museum of Comparative Zoology, 

 which has been intrusted to me for examination and description, con- 

 tains a very large number of specimens from widely different localities. 

 The majority of these were dredged in the Florida Straits and in the 

 Caribbean Sea, under the auspices of the U. S. Coast Survey. There is 

 also a foreign collection, which mainly consists of specimens obtained by 

 the U. S. and N. P. Exploring Expeditions. Many of them are from 

 localities that I had not previously known as the homes of Comatulae, 

 while others are merely additions to Comatula faunas already known to 

 me at particular localities. Except in these respects the foreign collec- 

 tion presents no features of special interest. 



The case is very different, however, with the collection obtained by 

 the "Blake" in the Caribbean Sea. In one respect, indeed, — the 

 number of duplicates, — it is superior to that made by the " Challenger." 

 A few species occur not only in great numbers, but also at several 

 localities; so that I have been able to study their range of variation in 

 a more satisfactory manner than it has hitherto been possible for me to 

 do in the case of any Comatula- but the common Antedon rosacea and Ant. 

 Eschrichtii. This opportunity has proved of immense value to me in 

 every way; and I am convinced that continued investigation will reveal 

 the existence of so many intermediate forms, that many types which 

 now appear quite distinct will prove to be specifically identical. This 

 has, in fact, been the ease with two of the speeies described by the late 



* -A few species obtained by the U. S. ('east Survey steamers "Corwin," " Bibb," 

 ami " Rassler" are also considered in this Report. 



VOL. 1\. \.>. 4. 



