2 Transactions. — Zoology. 



ophryon, from the glabella, and from the nasioii. In calcu- 

 latmg the cephalic and vertical indices, I have, however, used 

 only the second of the three, the glabello-occipital length, as 

 recommended by M. Broca, Sir William Turner, and others. 



Maximum Transverse Diameter. — This was taken as 

 directed by Broca. 



Glahello-iniac Lengtli, Basi-hregmatic Height, Steijlianic 

 Diameter, Biauricular Diameter, Temporal Diameter, Mini- 

 vium Frontal Diameter, Asterionic Diameter, Mastoid Height, 

 Length and Breadth of Foramen Magnum. — These were all 

 taken in accordance with Broca's directions. 



Horizontal Circumference, with its Pre-auricular and Post- 

 auricular Subdivisions. — In this also I have followed Broca, 

 carrying the tape round the skull at the level of the ophryon 

 in front, and the most distant occipital point behind. When 

 I began this series of measurements I took a second 

 horizontal circumference, from the glabella round the most 

 distant part of the occipital bone ; but, after an experience of 

 about sixty skulls, I gave this up, owing to the irregularities 

 introduced by the varying amount of projection of the ex- 

 ternal angular process of the frontal bone. 



Nasio-opisthic Arc, toith its Subdivisions — Vertical Trans- 

 verse Arc, superior and inferior. — These were measured in the 

 ordinary way between the points given by Broca. I found it 

 impossible, however, to measure the inferior arc of the trans- 

 verse vertical circiimference at all accurately with a stiff broad 

 tape, such as is used for the other curves, owing to the very 

 irregular character of the under surf ace of the skull. Broca 

 reconmiends twisting the tape somewhat, so that it may pass 

 between the styloid process and the spine of the sphenoid; but 

 even with this precaution my results were very variable, and 

 much in excess of the actual length of the curve. I found it 

 easy, however, to take a satisfactory measurement with a 

 piece of fine cord, and this was used accordingly. 



Cranial Capacity. — In estimating the cranial capacity I 

 have followed as closely as I could the directions given by Sir 

 William Turner in his report on the crania collected by the 

 "Challenger" expedition.* I was, however, unable to pro- 

 cure the two-litre graduated glass used by him, and in esti- 

 mating the quantity of shot contained in each skull I used the 

 litre and half-htre measures used by Broca. Each skull was 

 measured at least twice. 



Basi-alvcolar Length. — Here I follow Professor Sir William 

 Flower, j- Unfortunately the central incisor region was fre- 



* " ' Challengei- ' Reports," part xxix. : Report ou the Human 

 Skeleton— the Crania. 1884. 



t " Catalogue of the Museum of the Royal College of Surgeons of 

 England," part i., 1879. 



