No. 1. — Reports on the Dredging Operations off the West Coast of Central America to the Galapagos, to the West Coast of Mexico, and in the Gulf of California, in charge of Alexander Agassiz, carried on hg the U. S. Fish Commission Steamer "Albatross" during 1S91, LiEUT, Commander Z. L. Tanner, U. S. N., Commanding. XXIX. AND Reports on the Scientific Results of the Expedition to the Tropical Pacific, in charge of Alexander AcxASSIZ, on the U. S. Fish Commission Steamer " Albatross " from August, 1899, to March, 1900, Commander Jefferson T. Moser.U. S. N., Commanding. V. Reports on the Cephalopoda. By William E. Hoyle. The collection made by the "Albatross" during 1891 came into my hands in the year 1892. In the summer of 1893 I took the specimens to Copenhagen and spent some time studying them in the Zoological Museum of that city. I had then the pleasure and privilege of discuss-ing the more interesting forms with the doyen of students of Cephalopoda, Professor Steenstrup, and with his assistant, Dr. Posselt. Both these have since died, but the memory of their ready sympathy and helpful counsel remains and is hero gratefully acknowledged. I have also re-ceived assistance from my friend Dr. Georg Pfefter, for which I beg to tender him my sincere thanks. Some preparations of tlio luminous organs of Abndiopsis were exhibited at the meeting of tlie German Zo logical Society at Gotlingen in 1893, and also at the British Association in Nottingham in the same year, but after that, owing to tlie claims arising from the charge of a rapidly growing museum, no further progress was made for some years. The collection consists of thirty species (including a few forms to which I have not found it ])ossible to affix names), distributed in nine-teen genera, one of which (Froekenia) is new. Another {Pteri/giolcuthis) VOL. XLIII. — NO. 1 1