INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 297 



lists of the species found in tliem were made. Most of those thus as- 

 certained to be their ordinary food were traced to their natural haunts 

 from whence the fishes obtain them. 



9th. The parasites of fishes, both external and internal, were to be 

 collected and preserved for future study. 



A large collection of such parasites was made, but the internal para- 

 sites, which are very numerous, have not yet been studied. The inter- 

 nal parasites were collected chiefly by Dr. Edward Palmer. 



The map accompanying the present report serves to show the locali- 

 ties explored, and the extent of the labor in dredging and sounding. 

 The operations during the first six weeks were under the charge of Mr. 

 S. I. Smith, who remained until July 25. He was assisted by Dr. W. 

 G. Farlow, who also investigated the algae. Professor J. E. Todd, of 

 Tabor, Iowa, then took charge of the work for three weeks, until I was 

 able to join the party, on the 16th of August. During the remainder 

 of the season, until September 20, the operations were under my imme- 

 diate superintendence j but Professor A. Hyatt, of Boston; Dr. A. S. 

 Packard, of Salem ; Dr. Farlow, of Cambridge j and Professor D. C. Eaton, 

 of JS'ew Haven, gave very important aid in carrying out our investiga- 

 tions, and our thanks are due to all of these gentlemen for their assist- 

 ance. Several other naturalists were present, from time to time, and 

 cooperated with our i)arty in various ways. 



The dredging operations in the shallow waters of Vineyard Sound 

 and Buzzard's Bay were carried on at first by means of a sail-boat, but 

 during the greater part of the time by means of a steam-launch. The 

 dredgings outside of these waters, and off Martha's Yineyard, were all 

 done by means of a United States revenue-cutter, the steamer Mocca- 

 sin, under command of Captain J. G. Baker. Our thanks are due to 

 the officers of the Moccasin, who were very courteous, and gave us all 

 the facilities within their power for carrying out our investigations suc- 

 cessfully. Without this important assistance we should have remained 

 in complete ignorance of the temperature and peculiar fauna of the 

 deei)er waters off this shore, for the localities were too distant to be 

 reached by means of the steam-launch or sail-boats. 



The examination of the bottom was done by means of dredges of 

 various sizes, constructed much like those in general use for this pur- 

 pose; by "rake-dredges" of novel construction, consisting of a heavy 

 A-shaped iron frame, to the arms of which bars of iron armed with 

 long, thin, and sharp teeth, arranged like those of a rake, are bolted, 

 back to back ; a rectangular frame of round iron, supporting a deep 

 and fine dredge-net, follows just behind the rake to receive and retain 

 the animals raked from the soft mud or sand by the rake ; a trawl-net? 

 with a beam about fourteen feet long, made of stout, iron gas-pipe, and 

 having a net, fine toward the end, about forty feet deep, and provided 

 with numerous pockets; "tangles," consisting of an A-shaped iron 

 frame, to which frayed-out hemp-ropes are attached. The best form 



