Macalister — Lachrymo-jugal Suture in a Human Skull. 61 



which. I have examined. I have failed to find it in Chiromys and 

 Galeopithecus, as well as in the other Insectivores. 



Among Carnivores and Cetaceans no such suture exists ; and, in the 

 order Eodentia, the lachrymal bone shows a facial as well as an orbi- 

 tal surface ; but the zygomatic process of the maxillary, which in 

 these is largely developed, intervenes, and no suture occurs in any 

 form. 



In the allied order Proboscidea the lachrymal is small, ento-orbital, 

 with a tubercle ; but the small malar does not reach near to it. In 

 Hyracoidea the lachrymal is similarly arranged. 



Among Ungulates the Rhinoceros has the suture very distinct, 

 superficial. The Tapirs have a very well marked but shorter suture. 

 The Horses are similarly but more fully provided. 



All Artiodactyles have an extensive facial surface of the lachrymal, 

 and a long lachrymo-jugal suture ; largest, proportionally, in the 

 Bovidae, smallest in the Deer. 



Tylopoda possess a similar suture, but usually shorter and nar- 

 rower. 



In the Pigs the same arrangement obtains, the suture being 

 largest, proportionally, in the Phacochoerus, smallest in the Peccaries. 

 In the Hippopotamus the large, thin-walled lachrymal bone unites 

 by a moderately extensive suture, and sometimes anchyloses to the 

 malar. 



Among the Sirenia the large rough malar rests internally on the 

 scale-like, small, imperforate lachrymal in the Manatee, or on the 

 cubical, solid lachrymal in the Dugong. 



In Myrmecophaga the slender malar styles have a wide lachrymo- 

 jugal suture ; indeed, this is the chief attachment of the malar bone. 

 The Pangolin (Manis and Pholidotus) have the lachrymal fusing so 

 early with the maxilla as ' to be lost in distinctness ; but in young 

 skulls the lachrymal is well above the level of the imperfect zygoma. 



Armadillos have a very distinct and wide union of this bone, and 

 the large lachrymal in Orycteropus expands on the face for a con- 

 siderable extent. Eradypus has a distinct lachrymo-jugal suture, as 

 also is the case in the two species of Choloepus and in Chlamydophorus. 

 The lachrymal bone in Sarcophilus has a distinct lachrymo-jugal 

 union. In Thylacinus it is not so large, but arranged as in the former. 

 Phascolomys, Didelphys, Macropus, Petaurus, Phalangista, Halma- 

 turus, &c., all agree in the presence of such a suture. 



In my skulls of the Monotremes, Echidna and Ornithorhynchus, 

 sutural marks have been obliterated, but in Ornithorhynchus I think 

 I see traces of such lines, indicating a lachrymo-jugal contact. 



Thus among Mammals the suture is present in all below the 

 Hyracoids, absent in all above. In man there is even less tendency 

 towards its occurrence in lower and aboriginal races than in the 

 higher ; thus in the Veddahs, Negroes, Esquimaux, Puegians, Austra- 

 lians, the maxillo-jugal suture is much more vertical than in the 

 skulls of more ciArilized races, and the termination of the malar is 

 almost invariably external to the infra-orbital hole in all those. • 



