Feb. 13, 1890] 



NATURE 



347 



Rhinoceroses as of not more than specific importance, 

 this species should be included in the type genus. 



These Titanotherioids appear to have been most nearly 

 allied to the Rhinoceroses among existing forms, as is at 

 once apparent from the contour of the skull. According 

 to Prof. Marsh they were larger than the Dinocerata of 

 the Eocene, and nearly equalled in size the existing ele- 

 phants. The skull differs from those of the rhinoceroses, 

 however, in that instead of having one or two horns 

 placed in the middle line of the nasal region and having 



no sort of bor.y connection with the skull itself, it has two 

 large processes of solid bone in a transverse line 

 immediately over the nose, which were probably invested 

 with a horny sheath. 



The molar teeth are, moreover, unlike those of the 

 rhinoceroses, having excessively low crowns, and an 

 arrangement of the tubercles and ridges very similar to 

 that obtaining in the Tertiary genera Limnohyus and 

 Chalicotheriiini ; the first of which is certainly, and the 

 latter probably, a Perissodactyle, although the recent dis- 



Restoratio 1 of the skeleton of Titanothcriuiii robustiiiit (^'j nat. size). After Marsh. 



covcry that the peculiar claws upon the evidence of which 

 the supposed Edentate genus Macrothcritim was founded 

 are referable to it, render it a most aberrant type. 



The skeleton to which the original of the cast presented 

 to the Museum pertains was found in 1874 by the donor 

 in those beds of the Dakota Miocene known as the 

 Brontotherium beds, and it appears to be the best pre- 

 served example yet known. A restoration is given in 

 the accompanying woodcut. According to Prof. Marsh 



these deposits are several hundred feet in thickness, and 

 maybe separated into horizons, characterized by peculiar 

 species of Tztanotherudce. The remains of several 

 hundred individuals of this exclusively American group 

 have already been secured by the palaeontologists of New 

 Haven, and their English confreres look forward to the 

 publication of the sumptuous monograph in which Prof. 

 Marsh promises to illustrate these specimens with much 

 interest. 



NOTES. 

 There is some talk of a Committee of the Royal Society 

 being appointed to investigate the subject of colour-blindness, 

 and the proper methods of testing the colour-vision of employes 

 on railways. 



We may remind our readers that all applications for 

 assignments from the Government Grant must be sent to the 

 Assistant Secretary of the Royal Society on or before the last 

 day of February. AppHcations received after that date will not 

 be considered by the Committee of this year. 



An influential Committee has been formed for the purpose of 

 securing that the scientific and other friends of the late Dr. 



McNab, Professor of Botany in the Royal College of Science, 

 Dublin, shall have an opportunity of expressing their apprecia- 

 tion of his work and their respect for his memory. Through no 

 fault of his own, Prof. McNab was unable to make adequate 

 provision for his wife and five children ; and it is proposed that 

 the memorial shall consist of a fund, sufficiently large to be of 

 real service to his family. A good many subscriptions have 

 already been received or promised, and we hope that many 

 more may be forthcoming. Mr. Greenwood Pirn, Easton Lodge, 

 Monkstown, Co. Dublin, acts as hon. secretary ; Prof. W. N. 

 Hartley, F.R.S., Royal College of Science, Dublin, as hon. 

 treasurer. As Prof. Hartley has been obliged to leave Dublin 

 for some time, all communications should be addressed, and 

 cheques made payable, to the hon. secretary. 



