380 



SCIENCE 



[N. S. Vol. XXVI. No. 664 



surmised, take tte trouble to look up the orig- 

 inal reference (Linnseus, " Syst. Nat.," lOth 

 ed., I., p. 657). Having had confidence in 

 the above authorities I copied their blunder, 

 with the best intentions. So much for my 

 error. 



I shall adopt (but not "with pleasure") 

 Jager's name Bohadschia. I have for some 

 time been aware that Microthele probably has 

 precedence over AcUnopyga Bronn (for the 

 genus erroneously called Mulleria), but I hesi- 

 tate to accept it until the identity of Brandt's 

 species is settled beyond peradventure. 



Apropos the passing of Holothuria, for the 

 old and well-known genus of sea-cucumbers, 

 an amusing yet serious situation presents 

 itself. Naturally, if, as Dr. Gill points out, 

 Holothuria is really a Portugese man-of-war, 

 we can no longer speak of sea-cucumbers as 

 " holothurians," nor of the class as Eolo- 

 thurioidea. The word " holothurian " has 

 been, in its limited field, as useful as the more 

 familiar "mammal." And which of the sev- 

 eral synonyms should succeed Holothurioidea? 



W. K. Fisher 



Stanfokd Univebsitt, Cal. 



SPECIAL ARTICLES 



THE OCCDRRENOE OF MIDDLE TERTIARY MAMMAL- 

 BEARING BEDS IN NORTHWESTERN NEVADA 



In the summer of 1905 the writer received 

 from Mr. Robert L. Fulton, of Alameda, Cali- 

 fornia, several fragmentary bones and teeth 

 of Miocene mammals, said to have been ob- 

 tained at Virgin Valley, in northwestern Ne- 

 vada. Subsequently arrangements were made 

 to visit the locality in company with Professor 

 John A. Reid, of the University of Nevada, 

 Professor Reid very kindly made inquiry as 

 to the location of the beds, but was himself 

 unable to visit the region. In June, 1906, 

 the writer in company with Mr. Felix T. 

 Smith, of the University of California, visited 

 Virgin Valley for the purpose of making a pre- 

 liminary examination of the field. In reach- 

 ing the valley we were kindly assisted by the 

 employees of the Miller & Lux Company, and 

 in locating the most fossiliferous exposures 

 we were much indebted to Mr. T. H. McGhee, 



whose son, Mr. Edward McGhee, was the first 

 person known to have discovered fossil bones 

 in that region. 



Virgin Valley is situated in northwestern 

 Nevada, about 15 miles south of the Oregon 

 line and 40 miles from the California line. 

 Virgin Creek, which drains the valley, is a 

 tributary of Thousand Creek, emptying into 

 Thousand Lake, close to the northern border 

 of Nevada. The region about Virgin Valley 

 is semi-arid and is practically treeless. 

 Though no extensive search has been made 

 through the literature, I am not aware that 

 this region has ever been visited by any geo- 

 logical party. A number of explorers have 

 evidently passed near it to the north and to 

 the south. 



The valley of Virgin Creek is a basin with 

 a north and south trend, the fossil beds being 

 situated in a trough formed by an older series. 

 The older formation consists largely of tuSs, 

 ashes, and rhyolitic lavas. Superficially it 

 resembles a part of the Clarno Eocene series 

 of the John Day region to the north. On the 

 east side of the syncline, at Thousand Creek 

 Hill, a fine section of these beds is exposed. 

 Some of the tuffs in the upper part of the 

 series are exceedingly coarse, and pieces of 

 pumice in them are in many instances several 

 inches in diameter. The lower portion of this 

 series was not examined, but the materials 

 seem to be finer toward the base of the section. 

 Beds superficially similar to those on Thou- 

 sand Creek Hill cut off the southern end of 

 Virgin Valley on the other side of the syn- 

 cline, beyond the Virgin Ranch. At this point 

 they dip back toward the Thousand Creek Hill 

 to the northeast. 



The mammal-bearing Tertiary formation, 

 which is here tentatively designated as the 

 Virgin Valley beds, rests in the basin formed 

 by the older tuffs. Where the lower portion 

 of this formation rests upon the older beds it 

 has been somewhat disturbed, but the amount 

 of disturbance appears, at least in some cases, 

 to be less than that shown by the older series. 

 The inclination of the Virgin Valley beds on 

 the eastern side of the syncline may be largely 

 due to the development of an extensive fault 



