124 



THE POPULAR SCIENCE MONTHLY. 



for engines working with intermissions and 

 during brief spaces of time, the property 

 of liquid carbonic acid, of being always 

 ready for work, is of much importance. By 

 this same property, and since the mechani- 

 cal equivalent of electricity is very small, 

 such au engine is a very fit and cheap 

 source of electrical light. My method of 

 compression furnishes easily the required 

 tension for the conveyance of letters in 

 tubes, and the modern break-apparatus for 

 railways." Further, the author suggests 

 that his discovery might be turned to ac- 

 count in artillery, and in the construction 

 of submarine vessels. 



New Eocene Mammals. Prof. Marsh 

 is now contributing to the American Jour- 

 nal of Science a series of notices on new 

 and hitherto undescribed mammals found 

 in the Tertiary strata of the West. In the 

 March number of the Journal he describes 

 some new forms of quadrumana, a species 

 of his new order Tillodontia, three species 

 of rhinoceros, a new species of Brontothe- 

 rium, and various other extinct animal 

 forms. Among the quadrumana here de- 

 scribed, we have a new genus, Lemuravus, 

 closely resembling the lemurs in skeleton 

 and in the general structure of the skull. 

 The species L. distans was about the size 

 of the largest squirrels. During the late 

 raid into the "Bad Lands" of Nebraska, 

 Prof. Marsh found the lower jaw of a mon- 

 key, which indicated an animal about the 

 size of a coati ; it is the first specimen of 

 the order Primates found in that region, 

 and forms a new genus and species Zao- 

 vithecus robudus. The order TiUodonlia is 

 represented by the new species Tillotherium 

 fodiens. The animals of this order are 

 among the most remarkable yet discovered 

 in American strata. They seem to combine 

 characters of several distinct groups, viz,, 

 carnivoi'es, ungulates, and rodents. The 

 Tillotherium fodiens would appear to have 

 been about two-thirds as large as a tapir. 

 The rhinoceroses described are Dicerathe- 

 rium armai^im, D. nanicm, and D. advenum. 

 These animals had a pair of horns placed 

 transversely, as in modern ruminants,- as is 

 clearly indicated by large, bony protuber- 

 ances on the anterior portion of the nasal 

 bones. The D. aTmuitum, would appear to 



have been about two-thirds as large as the 

 Indian rhinoceros ; the D. nanum was 

 scarcely more than half the bulk of the 

 preceding ; while the D. advenum was half 

 the bulk of the Indian rhinoceros. The new 

 genus of Brontolkeridce is denominated An- 

 isacodon, and it is represented by the new 

 species A. montanus. According to the 

 author, this family consists of four well- 

 marked genera, viz., titanotherium, megace- 

 rops, brontotherium, and anisacodon. The 

 name Diplacodon elatus is given to a new 

 genus and species intermediate between 

 Limnohyus and Brontotherium. Two new 

 equine species from the Miocene are de- 

 scribed, and three new species allied to the 

 collared peccary. 



Prematnre Criticism. Mr. Proctor, in 

 the English Mechanic, calls attention to a 

 very curious piece of literary criticism 

 occurring, of all places in the world, in the 

 Atlantic Monthly. The critic is very severe 

 in his sentence upon " The Sun," " The Orbs 

 around Us," and other works by Mr. Proc- 

 tor, but the value of his judgment is im- 

 paired by the evidence Mr. Proctor fur- 

 nishes to show that it is not based on a 

 knowledge of what is contained in the 

 books. Among the works thus adversely 

 criticised is " Other Suns than Ours." Of 

 this Mr. Proctor says : " It may be as bad as 

 he says ; it may be ' trash,' and it may 

 ' confirm the evil prognostic of its title,' 

 but he might have waited till it was pub- 

 lished. Three years ago, when it was half 

 written, it was announced for early publica- 

 tion. Unfortunately for my critic (but 

 fortunately for me), he has been led to sup- 

 pose that the work accordingly appeared, 

 and might safely be abused. But a great 

 pressure of work prevented me from com- 

 pleting some stellar observations necessary 

 for its illustration, and the MS. still lies 

 unfinished in my desk. What a savage lit- 

 erary Herod a man must be who would 

 thus slaughter the book unborn ! " 



Fossils in Trap-Rock. The occurrence 

 of fossils in trap-rock, though not uncom- 

 mon, still awaits a satisfactory explanation. 

 Mr. E. A. Wiinsch, writing in a late number 

 of Nature, mentions several instances of the 

 presence of both plant and animal remains 



