MUSEUM OF COMPAKATIVE ZOOLOGY. 89 



belong to the same family as Liicifiiga, and consequently the remarks 

 made concerning the absence of barl)els in the latter will apply in a 

 measure to these genera, and with reference to Lucifuga receives more 

 force by the statement of Gtinther that they " are Erotula organized 

 for a subterranean life " (p. 647) ; and in the genus Brotula, which 

 has eyes, the snout is provided with barbels. 



Through the kindness of Mr. C. H. Townsend, naturalist of the 

 United States Fish Commission Steamer "Albatross," I have been 

 able to examine, though somewhat superticially, a specimen of Ipnops, — 

 probably the same species as the one above mentioned, — and, so 

 far as I could discover, Giinther's statement that it is " deprived of 

 organs of sight and touch" ('87, p. 190) is strictly correct. The same 

 author makes the following as a general statement on this subject : 

 " Special organs of touch are not more generally developed in deep-sea 

 fishes than in the littoral fauna. ... As such may be consideied . . . 

 the more or less detached rays of the pectoral fin of . . ., and especially 

 of Bathypterois, which possesses but rudimentary eyes." ('87, p. xxxi.) 

 And in another connection the same author (p. 722) says : " Beyond that 

 depth [two hundred fathoms] small-eyed as well as large-eyed fishes 

 occur ; the former having the want of vision compensated by tentacular 

 organs of touch, whilst the latter have no such accessory organs." 



I have not been able to find any direct statements concerning tactile 

 papillae on the several species of blind Silurids of South America men- 

 tioned by Gtinther (Packard, '86, p. 107), nor have we any knowledge 

 that such structures are found on Gronias, the blind representative of 

 the same family from Pennsylvania. 



The Integument. 



I was led to a study of the integument by the question having arisen 

 as to why the quantity of pigment should have diminished in it, while 

 under the same conditions of life it had increased in the eyes. That 

 such diminution had taken place iu the skin was inferred from the 

 generally much lighter appearance of the largest preserved specimens 

 as compared with the smallest. In the latter, the whole dorsal portion 

 of the body and head is covered with a great number of distinct pig- 

 ment cells (Fig. 1), while the large specimens never present anything 

 like so conspicuous a pigmentation ; and in the majority of cases they 

 appeal', on cursory observation, to be almost white. 



Closer examination shows, however, that the pigment is in reality 



