RECENT ADVANCES IN SCIENCE 241 



whole its affinities are with Centetes and Solenodon, themselves 

 very primitive types. But it is more primitive than these, and 

 should probably be regarded as ancestral to several of the living 

 families of Insectivora. 



The two species of Ground-sloths, to which reference has 

 been made, were related on the one hand to the much larger 

 Megalocnus, of Cuba, and on the other to the more primitive 

 Santa Cruz Megalonychidce. 



Quite apart from the value of this memoir to the palaeontolo- 

 gist and the zoologist, it furnishes most important evidence as 

 to the origin of the West Indies. For it shows that the rela- 

 tionships of most of the island mammalia run back to the 

 South American Miocene. Surveying the evidence as a whole, 

 the author inclines to the belief that the Antilles, up till late 

 Pliocene times, formed one continuous land mass, connected 

 with Central or South America, or both. And with this in- 

 terpretation most will agree. 



His conclusions are based, it may be remarked, on ample 

 material, and are supplemented by a number of very beautiful 

 text-figures and plates showing not only skulls, teeth, and 

 vertebrae, but also the appendicular skeleton. 



Prof. Henry Fairfield Osborn's Memoir, on the Equidae of 

 the Oligocene, Miocene and Pliocene of North America, will 

 ever be held in grateful remembrance {Memoirs of the American 

 Museum of Natural History ; New Series, vol. ii, pt. 1). All 

 the genotypes, types, cotypes, paratypes, neotypes, and topo- 

 types which have ever been figured are here reproduced in 

 facsimile. And more than this, many unfigured types are 

 here reproduced for the first time. The labour of compilation 

 which has been compressed into a little over 200 quarto pages, 

 and a separate volume of plates, would have been wellnigh 

 impossible for one author, but it has been accomplished in 

 brilliant fashion by the united efforts of six of the foremost 

 American palaeontologists. The condensed statements in re- 

 gard to the tooth morphology of the fossil Equidce, and the 

 section on the geologic horizons, and life-zones, will repay very 

 careful study. 



Yet another has been added to the number of restorations 

 of that remarkable reptile Triceratops. This one by Mr. Charles 

 Gilmore (Proc. U.S. Nat. Mus., vol. lv). The modelling of the 

 limbs in this latest attempt is by no means convincing. The 



