NARRATIVE OF THE CRUISE. 49 



The trawl again worked admirably, and brought up many specimens of fish, Echinids, 

 Asterids, Molluscs, Pennatulids, and other animals. The trawl after this was used through- 

 out the voyage for deep-sea work almost to the exclusion of the dredge. It produces 

 on the whole better results, and naturalists are much indebted to Captain Nares for 

 having had the courage to attempt the use in deep water of an instrument which must 

 fall on its proper side in order to work successfully. 1 On the other hand, it must be 

 remembered that the results appear to show that the trawl is not so favourable as the 

 dredge 2 for catching certain forms, such as Corals and Molluscs. 



The Pennatulida. — On the 31st January, at a depth of 2125 fathoms, a fine repre- 

 sentative specimen of the remarkable Alcyonarian genus Umbellida was taken. Umhellula 

 belongs to the suborder of the Alcyonarians, called by Professor v. Kolliker the Pennatulida. 

 It is a colonial organism, consisting of a bunch of polyps borne on the one extremity of a 

 long stem, provided with a flexible horny axis, the opposite end being implanted firmly in 

 the deep-sea mud. In the prpsent specimen, which proved to be a new species, named by 

 Professor v. Kolliker Umhellula thomsoni, the stem measured 36 inches in length. It is 

 shown in fig. 10 (cut short). Many of the Pennatulida are known to be phosphorescent, 

 and in this specimen of Umbellida, when taken from the trawl, the polyps and the 

 membrane covering the axis of the stem exhibited a most brilliant phosphorescence. 

 A like phenomenon was observed in the case of many other Alcyonarians obtained from 

 the deep sea, — a matter of peculiar interest in connection with the presence of eyes in 

 certain deep-sea animals, which inhabit a region totally devoid of any other source of light. 



Umhellula was long one of the rarest of zoological curiosities. The first specimens 

 ever described were obtained on the coast of Greenland, early in the last century, by 

 Captain Adriaanz, commander of the " Britannia," while on a whale-fishing expedition ; 

 on this occasion two specimens were found adhering to the sounding line at a depth of 

 236 fathoms. These were described by M. Christlob Mylius, and one of them was again 

 described in the Philosophical Transactions for 1754, in a letter from Mr. John Ellis to 

 Mr. Peter Collinson, " Concerning a cluster-polyp found in the sea near the coast of 

 Greenland." Mr. Ellis compared it to the " Encrinos or Lilium lapideum of the curious 

 in fossils," and. indeed the resemblance to a Crinoid is not a little striking. For more 

 than a century the animal was not seen again, and it is only a few years since two 

 specimens were dredged in deep water during the cruise of the Swedish ships " Ingegerd " 

 and " Gladan," in the Arctic Ocean. These were described in 1874 by J. Lindahl as 

 two new species, — Umbellida miniacea and Umhellula pallida. 3 



1 Since this page was in type, Mr. Rathlmn {Science, vol. iv. p. 56, 1884) states that the trawl was systematically 

 used in scientific research by the U. S. Fish Commission in 1872, but he does not say whether they employed it for 

 deep-sea work prior to Captain Nares' suggestion. 



2 A comparison of the results obtained by means of the trawl and dredge will be given in the concluding Report 

 of the Challenger series. 



3 Lindahl, J., Om Pennatulid-sliigtet Umbellula, K. Svensk Vetensk.-Akad. Handl., Bd. xiii., No. 3, 1874. 

 (narr. chall. exp. — vol. i. — 1884.) 7 



