[15] ALBATEOSS EXPLORATIONS. 517 



treatment and crushing that they receive in the trawl, as well as by the 

 heat of the upper waters. The same is true of the more delicate species 

 in all of the groups. But the Mollusca having strong shells ; some of the 

 Echinodermsj and all the large, tough -skinned Actinians seem to be in- 

 jured or killed by the heat alone. It is probable, therefore, that but few 

 of the more delicate deep-sea animals will ever be seen alive by man, 

 and still fewer in a healthy living condition. 



HTDEOIDA. \JjLyliA.A^ 



The Hydroids are few in species, and not numerous individually in 

 the deeper dredgings. But at moderate depths, especially near George's 

 and Brown's Banks, a considerable number of northern and mostly well 

 known European species were obtained. Several interesting species also 

 occurred, some of them frequently, in 100 to 300 fathoms, off the south- 

 ern coast of New England. Some of these are undescribed. The most 

 abundant is a species of Tuhularia with coarse, yellow stems (T. in- 

 divisa f). A new species of Gladocarpus ( C. flexilis V., .fig. 29), with tall, 

 slender, pinnate, yellowish stalks is also very common. A large and 

 rather coarse hydroid, Galicella pUcatilis, fig. 30, is also rather common. 



ECHINODBEMATA. 



The Echinoderms were among the most abundant and interesting of 

 the deep-sea animals. About one hundred species were dredged by the 

 ''Albatross," many of which are new to our coast, though previously 

 dredged on the European side, or in the Caribbean Sea and still more dis- 

 tant regions. Others are undescribed forms. Among the Holothuriaus, 

 besides several species of Trochostoma and allied forms, there were two 

 gigantic species, belonging to a peculiar deep-sea family of which many 

 species were brought to light by the " Challenger " expedition. These 

 occurred in large numbers at several stations, mostly between 1,000 and 

 1,500 fathoms, in some cases more than a barrelful of one of them coming 

 up in a single haul. The largest and most singular one was a new species 

 of Benthodytes {B. gigantea V., figs. 31, a, h], a very large, massive species, 

 flat below and convex above, sometimes 18 inches long and 5 or 6 broad, 

 having a gelatinous, translucent appearance, but with a firm cartilagin- 

 ous texture when fresh. The cartilage-like walls of the body are very 

 thick, often an inch or more, and the visceral cavity is very small in 

 proportion. Owing to the dense and impervious, cartilage-like tissues, 

 this species is very difficult to preserve in alcohol,* the interior decay- 

 ing before the fluid can penetrate the tissues, even when the visceral 

 cavity is cut open. This has been dredged in 924 to 2,033 fathoms. 



* During the season of 1884 this and other large gelatinons species (Cejihalapods, 

 &c.) were preserved in much better condition by the use of ice-cold alcohol, kept in 

 tanks in the ice-room ready for immediate use. 



