HYMENODORA GLACIALIS. 169 



next obtained by the Norwegian North Atlantic Expedition, 1876-1878, at 

 several stations between Norway and Greenland, lat. 63°-80° N. All the 

 specimens were brought up from great depths, 452-1862 fathoms. It has 

 been taken more lately by the " Knight Errant " in Fiiroe Channel, and by 

 the " Albatross " off the east coast of the United States, lat. 37° 12' 20" N., 

 and 38° 19' 26" N., in 2369 and 2949 fathoms. The rudimentary condition 

 of the eyes would seem to indicate that the first specimen obtained was 

 brought to the surface by some accidental cause. It should be noted that 

 the identity of Buchholz's specimen with those more lately obtained rests 

 upon the assumption of error in Buchholz's figure, in which the abdominal 

 pleurae present a very different outline from that exhibited by the examples 

 subseqxiently secured. 



The uniformity of the conditions affecting animal life in the abysses of 

 the ocean the woi-ld over could not be exemplified more strikingly than by 

 the discovery of this animal in the tropical Pacific to within 1° 7' of the 

 equator. 



The number of teeth on the median keel of the carapace varies in diffei'- 

 ent specimens from one to four. The acumen of the rostrum also varies in 

 length, even in specimens from the same haul of the dredge. 



I have examined the structure of the second maxilliped in four speci- 

 mens, — two from Station 3383, and two (males) from Station 3433. In 

 the first two there is no trace of a podobranchia. In one of the specimens 

 from Station 3433 there is likewise no vestige of a gill, while in the 

 other, although it does not differ in any other regard, there is a distinct, 

 though small, podobranchia, composed of three plates, attached to the base 

 of the epipod. I therefore incline to the opinion that Professor Smith's 

 II. gracilis* characterized by the presence of a podobranchia on the second 

 maxilliped, was injudiciously separated from //. glacialis. It is to be observed 

 that the gill varies much in its degree of development in different speci- 

 mens of 11. gracilis. 



The telson in the Pacific specimens is seen in its integrity in but two 

 cases. In these the number of terminal spines is six and eight. 



* Ann. Rep. U. S. Fish Comm. for 1885, p. 680, Plate XII. Fig. 6, 1886. 



