6o Anurican Quarterly Microscopical Journal. 



Yucatan at the same depths, and that this fauna extends over 

 the greater part of the Gulf of Mexico. The mud about the 

 mouth of the Mississippi produces a decided change in the 

 fauna: in the deep water off the mouth of the river nothing of 

 importance was obtained by the dredge, but in depths of ii8 

 to 500 fathoms a number of interesting specimens were se- 

 cured. 



The following extract from a letter of Capt. Sigsbee, com- 

 manding the S. S. Blake, is of considerable interest : 



" On the first of April we put to sea again [from Havana] ; we steamed 

 about one and a half miles from the Morro (Eastj, and at the third 

 haul in 177 fathoms, from disintegrated coral rock bottom, up came six 

 beautiful " sea lilies." Some of them came up on the tangles, some on 

 the dredge. They were as brittle as glass. The heads soon curled over 

 and showed a decided disp)Osition to drop off. At a haul made soon 

 after we got more, and being afraid to put so many of them in the tank 

 together, I tried to delude the animals into the idea that they were in 

 their native temperatures by putting them into ice-water. This worked 

 well, although some of them became exasperated and shed some of 

 their arms. They lived in the ice-water for two hours, until I trans- 

 ferred them to the tank. They moved their arms one at a time. Some 

 of the lilies were white, some purple, some yellow ; the latter was the 

 color of the smaller and more delicate ones. All the sea lilies were ob- 

 tained from the same place." 



Some twenty perfect specimens of these beautiful Pentacrini 

 were obtained, representing the two recognized species, but 

 Prof. Agassiz is inclined to consider P. Mulleri as a younger 

 stage of P. Asterias. 



The work on the Blake has been of great value in determin- 

 ing the hydrography of the Gulf, as is well shown by a small 

 map prepared at the Coast Survey office. This map is made 

 up from the British Admiralty and U. S. surveys. 



" The map speaks for itself, and I need only call attention in a gen- 

 eral way to the princif)al features of the bottom. The most striking 

 characteristics of the Gulf are the two great banks extending the one 

 to the west of Florida j>eninsula and northward of the Florida Reef, the 

 other northward of the j>eninsula of Yucatan, the loo-fathom line in 

 both cases running in a general way parallel to the shore line and 

 forming the edge of the steep slopes of the deeper parts of the central 

 portion of the Gulf of Mexico. The rapidity with which the depth in- 

 creases is xtry strikingly shown to the north of the Tortugas, and to 

 the northward and westward of Alacran Reef, by the proximity of the 

 100 and 1,800 fathom curves, the eastern and southern edges of the 



