74 Dr Jacob on the Infra-orhital Cavities 



chalk of Yorkshire and the chalk of Ireland were very much 

 alike. The chalk of Ireland is stated to be so hard, that it is 

 known by the name of White Limestone. It is traversed by 

 slender veins of calcareous spar, which are more frequent in the 

 lower beds. It contains, though in very small quantities, kid- 

 neyrshaped nodules of iron-pyrites. The most striking of its 

 imbedded contents are said to be flinty nodules, which traverse 

 the mass in regular horizontal strata. 



The chalk in Ireland is stated in that paper to have some 

 other peculiarities ; but the above are exactly applicable to the 

 chalk of Yorkshire. 



On the Irvfra-orhital Cavities in Deers and Antelopes, called 

 Larmiers hy the older French Naturalists. By Arthur 

 Jacob, M. D., Professor of Anatomy in the Royal College of 

 Surgeons in Ireland.* 



In compliance with the recommendation of the Committee of 

 the Zoological Section of the Association made at the meeting 

 in Cambridge in 1833, I have availed myself of such opportu- 

 nities as have been afforded me of investigating the nature, 

 structure, and uses of these remarkable parts. To those alto- 

 gether unacquainted with the subject it is necessary to state 

 that they consist of two oval depressions about an inch and half 

 long, half an inch wide, and more than three quarters of an 

 inch deep in the majority of instances; situated on the side of 

 the face, and so near to the inner angle of the eye that they 

 create a very reasonable suspicion that they are connected with 

 that organ, and hence the term larmier applied to them. The 

 bottom of the depression is in most cases naked, but in some it 

 is jcovered with the hair, consequently it is composed of the skin 

 formed into an open sac, accommodated in a corresponding de- 

 pression in the bones of the face. In many animals provided 

 with this organ, a gutter, formed by folds of skin, leads so di- 

 rectly to it from the surface of the e)/e, that the passage of the 

 tears from the one place to the other appears inevitable ; while 



• Read at the Meeting of the British Association held in Dublin, August 

 1835. 



