Morphology of the Human Lachrymal Bone, Sfc. 235 



infraorbitalis transversa, and not uncommonly a sutura verticalis passes 

 downwards and forwards therefrom, either to the infra-orbital or the 

 accessory infra-orbital canal. 



The crest in a few instances projects as a sharp thin lamella, and 

 this has its free border either uniform or prolonged into spinons points. 

 The commonest place for such prolongation is at the junction of the 

 upper and middle third, a second often exists at the lower third, and 

 these two may coexist. These spines are still more frequent in the 

 bones showing the next variety. 



D. The carino-hamate form is nearly as common as the last, and in 

 the series of American crania in the Cambridge Museum it is found 

 in three out of each five. Among European crania I have found it 

 only in 27 per cent., and in 39 per cent, of the entire number exa- 

 mined. These vary from forms with a small acuminate spur that is, 

 strongly pronounced cases of the last form to those with a large 

 quadrate process projecting over the orbital ridge to the face ; this 

 last condition occurred in -^ of all the European crania examined, but 

 in 2^ f a ^ crania. This is the form which is most commonly asso- 

 ciated with accessory ossicles and sutures. In these cases, as well as 

 in the last series, the crista lachrymalis frequently begins above as 

 a rounded tuberous knob below the frontal suture, sometimes as a 

 sharp ridge, and this may be curved forward so as to arch sharply 

 over the lachrymal sac. This occurs in 2 per cent. In old bones this 

 region is usually thinned and rounded, owing to the distension of the 

 upper lachrymo-ethmoidal cell. Below this the crest at its upper 

 third is often prolonged into a spine for the attachment of the 

 lachrymalis posterior (attached not to the sharp edge, bat to the 

 posterior and outer surface of the spine), below which the crest is 

 less prominent and is indented into a bay, generally again becom- 

 ing prominent and merging into the hamulus. This arrangement of 

 the crest exists in one-sixth of the bones examined. 



In 2 per cent, of hamate bones the border of the crista is reduced to 

 a thread 1 millim. in breadth ; but I have not found this form to be 

 constant among negroes, as Sommering regarded it to be (Weber- 

 Hildebrand, II, 401). 



In three cases I found examples of the second spine above the 

 hamulus at the lower third of the crista, similar to that described by 

 Schwegel (" Henle u. Pfeufer's Zeitschrift," III Reihe, V, 1856, 

 p. 866). 



In five cases there was a perforation through the root of the 

 hamulus, traversed in one instance by a branch of the infra-orbital 

 artery. The hamulus is pierced by one or two holes in 2 per cent, of 

 specimens, and these transmit similar vessels. 



In one Malay skull the hamulus was wide and deep, reminding one 

 of the condition in many catarrhine monkeys. 



