290 



SCIENCE 



[Vol. XIX. No. 485 



39, 1893. The eastward prolongation of the ancient bluflfs is 

 probably not continued in the line yx. but bending east about 

 where the turn occurs in the courses of Lost Creek and Shell 

 Creek. The former is a considerable stream so long as it has the 

 impervious Cretaceous shales for a substratum, but soon disappears 

 when it encounters the deep mass of silt in the Platte valley. 



There is no evidence, so far as I know, that the Platte has ever 

 shifted out of its old rock bed, except during the transient episode 

 at Sand Creek. The existence of a gorge excavated in Mesozoic 

 and Paloeozoic rocks, once five hundred feet deep though now 

 silted up to its brim, is the best reason for its present course. Nor 

 can any inferences respecting the influence of rotation be drawn 

 from the trend of this gorge, for the reason that a considerable 

 part of it was formed by a stream which flowed west. When the 

 Platte first stretched across the plains, its several parts of different 

 ages and opposite flow being united in one great river, it found a 

 ready-made channel, to which it has, in the main, steadily ad- 

 hered. The hypothesis that it once flowed in the channel of the 

 Loup fares badly in the light of the facts, and, looking across to 

 the southward, we find no evidence that it ever flowed in any of 

 the numerous heads of the Blue, as suggested by Professor Davis. 

 None of them has any marked pre-eminence over the rest, and all 

 of them are slight recent furrows, mostly below the level of the 

 Platte, so that it must have shifted up-hill if it once flowed in 

 them. 



The suggestion that it once flowed in Prairie Creek falls into a 

 different category, since this stream is within the old i-ock trough. 

 But it is a mere pin scratch in a wide alluvial plain, any other 

 line of which is just as likely as that to have been the flow-line of 

 the Platte at some period. Of course this great river has shifted 

 about within its rocky gorge. The most signiticant fact in respect 

 to the influence of rotation is that it now, in many places, crowds 

 upon tbe south bluffs, as shown in Fig. 2. 



It is agreeable to have the concurrence of Professor Todd in my 

 opinion that " the Loups did formerly flow through to the Platte.' 

 I trust he will not recede from this harmonious attitude in conse- 

 quence of finding it impossible to put the Platte over into the 

 Loup in order to get them together. Strictly speaking, however, 

 that is not impossible. A big canal would accomplish it liter- 

 ally. The real dilHculty is to get the Platte back to its present 

 higher channel. It is not now a constructive stream, building up 

 its bed above the surrounding country, else we might suppose that 

 it had shifted to its present position and then built it up above the 

 Loup. It has not probably been a constructive river at any time 

 since the Rocky Mountain uplift emptied Lake Cheyenne, and 

 gave the Platte such a steep gradient that it is able to accomplish a 

 little vertical erosion in spite of its great burden of sediment. It 

 trembles on the verge between vertical erosion and deposition, the 

 balance inclining to the former, but so slightly that it main- 

 tains its levels with great steadiness. Herein lies another reason 

 for doubting that great changes of level have recently occurred in 

 its valley. L. E. Hicks. 



Lincoln, Neb. 



Sistrurus and Cro alophorus. 



On page xxvi. of the introduction to a work on North American 

 Reptiles, in the "Memoirs of the Museum of Comparative Zo- 

 ology," VIII., 1883, the name Sistrurus was applied to one of the 

 two genera of rattlesnakes because Crotalophorus, the previous 

 title, was a synonym for Crotalus, the other genus. Professor 

 Cope, in his latest paper on the serpents, Proc. U. S. Mus. , 1893, 

 p. 634, objects to the change in these terms : ' ' Mr. Garman has 

 named this genus Sistrurus, on the ground that the name Crotalo- 

 phorus was preoccupied at the time it was employed by Gray. 

 This does not, however, seem to be the case. It is true that Lin- 

 naeus uses it instead of Crotalus in the sixth edition of the Systema 

 Naturee (1748, p. 35), but the system of nomenclature thus adopted 

 is not binomial, so that the names are not authoritative as against 

 later ones." This makes a considerable display of lack of caution, 

 to say the least of it. If use by Linne in the sixth edition of the 

 Systema (as also in the seventh and the ninth editions, and the 

 Amoenitates) was all that bore on the question there might be 

 nothing to say. But in proposing the new name I had in mind 



more than appears from the citation. Linne and Gronow only 

 were mentioned. The dates for the latter were 1756 and 1768, 

 which brings us within the range of the tenth edition, 1758. 

 Gronow might be put aside as unsound binomially. If so, I still 

 had Houttuyn, 1764, who certainly regarded the names as synony- 

 mous, for he says, " De geslagtnaam deezer slangen, Crotalo- 

 phorus, en by verkorting Crotalus, is afkomstig van den ratel, dien 

 zy aan't end der staart hebben." But, again, if not allowed to go 

 farther back than the twelfth edition, 1766, there was another 

 authority for Crotalophorus instead of Crotalus, Vosmaer, 1768, 

 according to whom, " De Heer Linueus geeft de benaaming van 

 Crotalophorus aan dit geslacht, in het welk hy drie onderscheidene 

 soorten heeft opgeteekend, die hy Horridus, Dryinas en Durissus 

 noerat." 



Under the name Crotalophorus, 1748-68, neither Linne, Gronow, 

 Houttuyn nor Vosmaer included any of the species of the genus 

 defined by Gray, 1835, with the same name. That they were not 

 binomial authorities may be urged against Linne and Gronow, 

 but not against Houttuyn and Vosmaer, who, though they re- 

 tained the earlier name, adopted the genus and the species from 

 the tenth edition of the Systema. Linne dropped Crotalophorus 

 for Crotalus in 1758. In 1766 he described the first species of the 

 other genus, placing it in Crotalus, where it was kept by most au- 

 thors until removed by Gray. The necessity of the change I 

 have made in the name of Gray's genus is best shown by a con- 

 cise view of the synonymy for the two genera. 



Crotalus. 



CaudisonaUnn., 1735-47; Laur., 1768; Flem , 1833; Cope, 

 1861-71; Coues, 1875. 



Croia^op/iOrMs Linn., 1748-56; Gronow, 1756-63; Houtt., 1764; 

 Vosm., 1768. 



Crolnlius Linn., 1754. 



Crotalus Linn., 1758-66; Daud., 1803; Merr., 1820; Gray, 182i- 

 49; Fitz., 1836^3; WagL, 1830; Holbr., 1843; Bd. and Gir., 

 1853-59; Dum. Bibr., 1854; Cope, 1859, 1875-93; Garm., 1883. 

 (Many omitted. In most cases, from 1766 till 1835, a species of 

 Sistrurus was included.) 



Crotalinus Raf., 1815. 



Uropsophus WagL, 1830; Gray, 1831-49; Fitz , 1843. 



Urocrotalon Fitz. , 1843. 



Aplnaspis Cope, 1866-75. 



Aechmophrys Coues, 1875. (The last four apply to particular 

 species.) 



Sistrurus. 



Crotalophorus Gray, 1825-31, 1849; Holbr., 1843; B. and G.. 

 1853-59: Cope. 1859, 1886-93. 



Caudisona Fitz., 1826-43; Wagl., 1830; Bon., 1831; Gray, 1842; 

 Yarr., 1875; Cope, 1875-80. 



Crotalus Flem., 1822; Cope, 1860; Coues, 1875. 



Sistrurus Ga.rm., 1883. 



S. Gaeman. 



Mus. Comp. Zool., Cambridge, Masa. 



"Scientific" Genealogy— Rejoinder, No. 2. 



Quite recently I contributed to these columns {Science, Vol. 

 XIX., No. 476. " 'Scientific' Genealogy— A Rejoinder."— Veritas.) 

 a brief paper intended to curb some tendencies prevalent in genea- 

 logical circles, notably untenable assumptions regarding family 

 traits and likenesses inherited. 



Since the appearance of the above article several criticisms have 

 been sent to this magazine — rather surprising to ''Veritas" for 

 the reason that they indicated a lack of acquaintance with what 

 he opposed in the article. 



General discussions of biology, breeding of animals — human 

 and brute — are, I doubt not, of interest and profit, only, — they 

 hardly touch my point in the argument, and it is important in 

 open discussion to keep to the question, — so many readers mis- 

 take a rambling generalization for argument and fact. Then, 

 too, I object to portions of the article by "Enquirer," namely, 

 p. 155, paragraphs 1 and 4, as mistakenly quuting my views (for 

 light on which my article is in evilence) and also to his last para- 



