80 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
Table of dimensions of skulls of RYTINA GIGAS (Zimmerm. ) not including those of the lower 
juw. 
Collectors’ No. 
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- - a a 
Tee: 
=|5|8/18/8;}8|]s8)| 2] ge 
@ Le a — oo | = — a 5 
. “2 nl cr al sl tl rc =} 
Measurements. = 6 S S$ S ¢ $ 6 a a 
OO Spr) See ee he ey ee 
A I mm I H ~ ml mH 5 5 
1] 2 2 o o Ss | 2 2 7) 2 
a oe 0 ty oD 1) ay oe ep i) 
Ea 3) ca) ro) 2 2 .) os m3 
2 Az Je 2 n= Ho ed eee 8 5 5 
P| Fle|zZie|e/e) E/E le 
= nD 77) nN D n 7) R <4 < 
Supposed'sex 222 ts. <2) vs vescs sce os roe ros fof of fof 2 5d | 3Q 
mm.|mm.|mm.|mm.\mm.' mm. mm.) mm. mm.| mm. 
1. Total length from superior margin | 
of foramen magnum to tip of in- 
MERMAXT Ly seo oe ace omens ast 676 | 654 | 636 | 672*| 625* 655* 645) 662) 653 654 
2. Greatest breadth at zygomatic | 
BCH ts eriente canciones Geena 353 | 353 | 342 | 360 | 338) 330 324) 331) 349 328 
3. Distance of tips of occipital ma- 
millar processes..---...--------. 270 | 266| 266 | 257) 264 | 240 261 | 258} 245 253 
4, From mamillar process to poste- H | 
rior angle of zygomatic process 
of supramaxilla.......-.... .-.. 305 | 280 |) 280 288) 280| 295 284 | 285 | 287 288 
5. Greatest breadth of occipital at 
base of mamillar process ....--- 261 | 277 | 254 | 246! 258) 269) 250 | 260) 259 260 
6. Breadth of basilar part of occiput | | | | 
at posterior ead: of eminentia | | a FA 
CURE IBEDT ee oer secea ene eee 47; 61 45 50; 46 51) 48 45 50 48 
7. Breadth of condyloid rami of occi- | | 
ATE otek eile CA EN ke, 51| 54) 42). 47) 45) 52) 47 1 datas 48 
8. Closest approximation of condyles | 
beneath foramen magnum 66) 63 75 51 68 78 67 80 65 75 
9. Greatest distance of exterior mar- | 
ginsiof condyles!) =2 ie. eer 222} 233 | 215 | 218 | 210] 215] 205! 220) 220 213 
10. Distance of exterior, posterior | 
angles of parietals ........--.--. 152 | 177} 153] 163 | 148 | 140} 129] 145; 159 138 
11. Distance of exterior, anterior | 
angles of parietals .....--....... 995), 112 | LOL I erO0, 96 | 100 99; 105 98 
12. Distance of the alveolar margins 
at exterior tip of intermaxillar | 
process of supramaxilla......-... 84 91 81 78 73.4) © 76D snare 73 81 71 
13. Distance of tipsof nasal processes 
of intermaxillaries ...... Nore 74 | 73 692) 74) 77 | 58 59| 551 73 57 
14. Lengthof articular surface of nasal | | 
process of intermaxillaries...... 1K ia BBD | eee aie 140 | 1388 | 127| 186! 118? 140 127 
15. Breadth of intermaxilla at anterior 
angle of nasal aperture ..-.....- 74 74 72 69| 65) 59 57 | St) Laie 
16. Distance of posterior apices of | 1" weal | 
zygomatic processes of supra- | | 
maxilla from each other. ..... ---| 289] 280) 263 | 270) 270 | 265 | 232) 252 | 274 | 250 
* These specimens have the beak a little defective. Being broken in the same manner, the missing 
part in each has been estimated to make 10™™, 
This table proves the fact that while the longitudinal dimensions are 
almost identical in the supposed two sexes, most of the transverse dimen- 
sions anterior to the occipital bone are much smaller in the female than 
in the male, the difference averaging from 7 to 25 per cent. of the smaller 
dimension. 
The average measurements give a very clear representation of these 
relations, and they are therefore very serviceable in trying to express 
the difference in a diagnosis, because they eliminate the individual varia- 
tion.* 
*T recall here Humboldt’s words: ‘‘ Dass bei allem Beweglichen und Verinderlichen 
im Raume mittlere Zahlenwerthe der letzte Zweck, ja der Ausdruck physischer Gesetze 
sind, welche uns das Stetige in dem Wechsel wis in der Ershcheinungen zeigen.” 
a a 
