43^ 



NATURE 



[September 7, 1893 



pathological. My restoration will be found in the American 

 Journal of Science for October, 1 892, and in the Geological 

 Magazine for April, 1893. 



The third figure given by Mr. Lydekker is a reduced copy of 

 my restoration of Sle^osaiints ungulalus, published in August, 

 189 r. This reptile he calls Hypsirophus, giving that name 

 priority over Stegosaurus, but without citing any authority for 

 such a statement. A single reference to the literature would 

 have proved this to be a mistake, as Stegosaurus was published 

 by me in 1877, as above stated (American jfournal of Science 

 (3), vol. xiv. p. 513), while the name Hypsirophus was given 

 by Cope in 1878 [American Naturalist, vol. xii. p. 188). 

 Another error of less i.nportance is in regard to the specimen 

 on which the restoration is based, although this was clearly 

 stated in the description accompanying my figure. The type 

 specimen of Stegosaurus ungttlatus Mr. Lydekker apparently 

 confuses with a second skeleton, of a different species, which 

 was even more perfect when found. 



The fourth restoration given is a reduced copy of my figure 

 of the skeleton of Triceralops prorsus, which, like the preceding 

 restorations, has already been published by me, both in the 

 American jfonrna! of Science a.r\A in the Geological Magazine. 

 Here again Mr. Lydekker rejects my generic name Triceratops, 

 and even puts that and another genus of mine (Ceratops) as 

 synonyms of Agathaumas without giving any reasons for doing 

 so. The type specimens of the literature would show any candid 

 anatomist that the three forms named, and another which I 

 called Torosaurus-, are all distinct genera, separated by well- 

 defined characters. These characters I have given in detail in 

 the American Journal of Science, accompanied by accurate 

 figures of the forms I have described (vol. xliii. pp. 81-84, 

 plates ii. and iii. , January, 1892). 



Tne remaining restoration given in Fig. 5 represents a well- 

 known skeleton of Iguanodon in the Royal Museum of Belgium. 

 In regard to this figure I have at present nothing to say, except 

 that I have carefully studied the original specimen and those 

 found with it, having made several visits to Brussels for this 

 purpose. 



The omissions from this article are perhap; ai noteworthy as 

 what it contains. No reference is made to two restorations of 

 American Dinosaurs which I have recently published ; 

 Claoaurus from the Cretaceius, and Anchisaurus from the 

 Tria-sic, although each is based on a nearly perfect skeleton. 

 Both of these restorations have appeared in the American 

 Journal of Science and also in the Geological Magazine within 

 the past year. Mr. Lydekker likewise omits the restoration of 

 Megalosaurus, which he has lately given to the public, although 

 many paUeontologists would be glad to know more about it, 

 especially about the remains on which it is based. 



Mr. Lydekker begins his article by referring to the discour- 

 agements of paloe)ntologists in the investigation of fossil verte- 

 brates, but emls with some words of encouragement. He might 

 have added that one discouragement to active workers who de- 

 vote years to exploration and study is to have the results of their 

 labour used without due credit, or disparaged by those who do 

 not understand them. O. C. Marsh. 



Vale University, New Haven, Conn., August 15. 



Insects Attracted by Solanum. 



Sir John Litbbock, in his " British Wild Flowers in Re- 

 lation to Insects," remarks (p. 133) that Solanum is little 

 visited by insects. Darwin, in "Effects of Cross and Self 

 Fertilisation," has some observations (p. 387) to the same effect. 

 It will therefore be useful to record that, however it may be 

 with European species, an abundant Solanum of New Mexico 

 is very attractive to insects. The species in que>tion is S. 

 elceagnifolium, Cav. , which has deep lilac flowers not unlike 

 thoie of the potato. I was especially successful in capturing 

 interesting aculeate hymenoptera on this plant, as the following 

 Hit will show. All listed were taken in Las Cruces, and all 

 (except the M gacilissa, July 12) on July 13. 



Hymenoptera taken on Solanwn elceagnifolium, 1893. 



Artimophila pruinosa, Cr. 9 . 



,, varipes, Cr. 



Anthophora urbana, Cr. 9 ■ 

 Haliclus, sp. 9 . 



NO. 1245, VOL. 48] 



Megacilissa gloriosa. Fox. 

 Melissodes mentiacha, Cr. var.?9 

 Myzine frontalis, Cr. MS. 

 Mysson texanus, Cr. 9 . 



,, n. sp, 

 Odynerus bravo, Sauss. (new to U.S. fauna). 

 Pelcposus servillei, Lef. 

 Plenoculus, n. sp. 



Sphoerophthalma coccineokirta, Blake, <5var. 

 Stizus agilis, Sm. 



,, flavus. Cam. (new to U.S. fauna). 

 Tachysphex, sp. 9 . 

 Tacky tes elongatm, Cr. <5. 

 Trypoxylon texense, Sauss. 



For the identifications of the species I am indebted to Mr. 

 W. J. Fox. T. D. A. CoClvERELL. 



Agricultural College, Las Cruces, New Mexico, U.S.A. 

 August i6. 



Old and New Astronomy. 



In your notice of the "Old and New Astronomy," your re- 

 viewer has, I think, misunderstood the passage with respect to 

 reflecting telescope.-, on p. 45, which he refers to as indicating 

 that Mr. Proctor supposed that the image in the principal focus 

 of a reflecting telescope was affected with chromatic aberration 

 or fal.'^e colouring. Section 97, to which I conclude ycur re- 

 viewer refer.';, evidently refers to the magnified image which 

 enters the eye of an observer when a " real image of an object 

 is submitted to microscopical examination." 



No one who knew Mr. Proctor could suppose him to make 

 such a mistake ; and that he was perfectly well aware that the 

 image thrown by a reflector was not affected with chromatic 

 aberration, would, I think, have been evident to your reviewfet. 

 if he had read to the bottom of the page, where in Section lOI 

 Mr. Proctor says : — "Newton supposed that it was impossible 

 to get rid of this defect {i e. chromatic aberration), and therefore 

 turned his attention to the construction of reflectors," a clear 

 proof that Mr. Proctor was in no doubt upon the subject, and 

 only referred in the previous passage to the false colouring of 

 an image formed by a lens. 



S. D. Proctor-Smyth. 



8 Duncairn Street, Belfast, August 23. 



Mrs. Proctor-Smyth is in error in .supposing that my note 

 referred to Section 97 of " Old and New Astronom)." I 

 referred to Section 100, in which the author says " the pencil (rf 

 light proceeding from a point such as P, Figs. 14, 16, and 18, 

 consists of rays of different refrangibility, and therefore net con- 

 verging to a focal point such as p but to a focal line in the axis ef 

 the pencil." (The italics are mine. ) Fig. 18 is a diagram of the 

 formation of a real image by a reflector. The reference to 

 Fig. i8 may have been a slip ; if so, it should have been cor- 

 rected in the completed volume, as otherwise the .student, 

 reading the subsequent p.aragraphs, to which Mrs. Proctor- 

 Smyth refers, is confused as to what the author really means, 

 and is doubtful whether the reflector does or does not .suffer 

 from chromatic aberration. The Revikwer. 



Suicide of Rattlesnake. 



Another question raised by the late snake story i.s, Ho» 

 long does it take to drown snakes? Some of the non-poisonous 

 kind at the Zoological Gardens, in certain states of the weather, 

 are fond of hanging themselves over the edge of their tank, 

 with their heads immersed in the water, for as long a^ an hour 

 together. E. L. Garbett. 



August 29. 



THE EARLY ASTERISMS. 

 I. 



NOT very many years ago, when the literature of 

 China and India was as a sealed book, and the 

 hieroglyphics of Egypt and the wedges of Babylonia were 



