DEPARTMENT OF MARINE BIOLOGY. 203 



possibly and probably represents this stage. It was 33 mm. long and was 

 taken from the stomach of a sea bass (Serranus) off the North Carolina coast. 

 The bass had probably taken it on its way down to the bottom or shortly 

 after its arrival there. 



As the season passes into fall the young of Astroscopus seek the beaches and 

 pass into the bays and sounds. At this time they show a tendency to "school" 

 together, as shown by their capture in the seine in groups of from 2 to 30 or 

 more, late in the fall, when they are not over 2| inches in length. After a 

 short winter rest they appear again sometimes in "schools," sometimes alone, 

 and have reached a length of from 2 to 3| inches in April. One was captured 

 at Beaufort, North Carolina, by Miss Rowena Radcliffe after it had attempted 

 to swallow a Fundulus majalis that was longer than itself. 



During the next year the fish attain a length of 4 or 5 inches, and even when 

 6 or 7 inches long they show the tendency to "school," being caught in com- 

 pany with others of about the same length. 



In this history of its general seasonal movements the fish compares almost 

 exactly with several other bottom fish of our coast, as the lump-fish, the 

 various pufTers, and many others. 



The development of the electric organs is late and only really begins when 

 the fish starts for the bottom. Enough of it has been seen to say that the 

 organ consists of tissues that have formerly been a part of at least three of the 

 eye muscles on each side, the edge of the muscle in each case going through 

 peculiar changes and separating from the main muscle mass while it hyper- 

 trophies into elements many times larger than the remaining muscle fibers. 



Summary of Work on the Fishes of Tortugas, by E. W. Gudger. 



The work of former seasons on the fishes of Tortugas and surrounding parts 

 was continued during my stay at the Laboratory in the month of July. 



Among sharks two specimens of Hypoprion signatus, male and female, were 

 taken in Key West Harbor at the same spot and at an interval of only a few 

 hours. They were probably mates, for it is believed that selachians go in 

 pairs, male and female. This shark, the writer believes, is new to the waters 

 of the United States. 



Two female specimens of the dusky shark, Carcharhinus ohscurus, were taken 

 at Key West, but neither carried embryos. These sharks are sluggish and 

 inert and hence are easily run down and harpooned. 



A 10|-foot specimen of the more active tiger shark, Galeocerdo tigrinus, was 

 harpooned after a hard chase. It offered great resistance and seized the stem 

 of the launch in its jaws, holding on until its snout had been severely 

 cut with repeated blows of a hatchet. It finally tore loose from the harpoon, 

 but its escape was prevented by a lashing around the small of the tail. This 

 shark abundantly justified its name by the fierce resistance it offered and, like 

 three others captured by the writer, showed a marked disposition to roll itself 

 up in the harpoon line. This habit was corroborated by a number of Key 

 West fishermen who were interrogated separately. 



Two or more shark hooks were kept baited at Loggerhead and Garden Keys, 

 Tortugas, but, though numbers of sharks were seen off the laboratory and 

 in the lagoon of the atoll, only one was hooked. However, baits were regu- 

 larly taken and several fish were evidently caught but got away, as was 

 evidenced by the straightened-out hooks. 



A Hypoprion hrevirostris was securely hooked, but when I went out to bring 

 it in I found only the head and shoulder parts; the remainder of the fish had 

 been eaten by a larger shark which had been seen by one of the laboratory 



