iMKMOlKS UF THE NATIONAL ACADEMY OF SCIENCES. 221 



rpou iiiKpei-tiii;;: tho i)elvos wc liiul them forming two groups. Iti the one group are Nos. 

 M. (!, II. 7, II. 14, H. 18, 11. Ill, II. :.'.-.. II. -11, and 11. 72. Tlieso pn-s.-ntall tin- ordinary cLanntc'r- 

 istics of the male pelvis. In the other group we lind Nos. 11. 1. 11. ."), M. S, II. 10, II. 15, II. ;J(J, 11. 

 ;«t, 11. 4.j, H. 57, ami II. 59. These rejiresent females. 



No. II. !•(! is the jielvis of a very young i)er8()n. The ilia, isciiia, and i»ul)es are not eoossilied. 

 Hence, we do not attempt to determine its sex, and omit it from our ealculations. 



The data furnished hy tlie hreadtii-height index and the index of the superior strait aecord to 

 the Saladoans a lii.i;ii plaie in the human series. With regard to the breadth-height index, both 

 the males and the females stand at the top of the scale. Witli regard to tiie index of the superior 

 strait, the females staml at the highest (arithmetically tlio lowest) end of the scale al)ove the 

 Europeans. The males occupy a medium position. 



The other indices are of use in comparing the sexes, but we have never .seen any (;omi)arative 

 data conceridng them in print. 



We have prei)ared four ordinations, one for ea(;h index. These, especially the indices of 

 pubo-ischiatic depth ami that of sacral length, show very i)rettily the natural grouping of the sexes. 

 (See Tables LXii to i,xv, inclusive.) 



Note. — In the table of mea.suremeuts of the pelvis the abbreviation "5 v" is occasionally found 

 after figures concerning the sacrum. This is used in cases where the sacrum consists of six verte- 

 brip, to indicate that only five of them are measured. 



LIST OF MEASUREMENTS. 



I. Coitjiigata externa. — Anteroposterior maximum diameter of tlie pelvis: From the antero- 

 superior part of the symphysis jtubis to the summit of the sjiinous process of the first sacral 

 vertebra. 



3. Crest iriilfh. — Width between the crests of the ilia: Indicated by the greatest width between 

 the external surfaces of the crests. • 



3. Atitero-fiupcrior .spinal iridth. — Width between the anterior-superior spines of the ilia: From 

 the center of the most prominent part of one .spine to the corresponding point on the other. 



■i. Postcrostiperior spinal *(cidtlt. — Width between the posterior-superior spines of the ilia: 

 Measuring from the center of the most prominent part of one posterior- superior spine to a similar 

 l)oint on the other. 



5. Anteroposterior diameter of the brim. — From the anterior-superior margin of the promontory 

 of the sacrum to the most adjacent point of the symphysis pubis. 



6". Transverse diameter of the brim. — Maximum width measmed at right angles to the antero- 

 posterior diameter. 



7. Antcro-posterior diameter of outlet. — Width between the center of the anterior-inferior 

 margin of the body of the fifth sacral vertebra and the most adjacent point of the symphysis pubis. 



s. Transverse diameter of outlet. — The maximum width of the pelvic outlet measured at right 

 angles to the antero- posterior diameters of the outlet, between the most widely separated points, 

 on lines passing parallel to the brim line from the spines of the ischia to the lower ends of the 

 obturator foramina. 



9. Sciatic width. — Minimum distance between the sciatic spines. 



10. Pelvic heiijht. — Maximum length of the innominate bone or pelvic height. 



II. Iliac breadth. — Maximum breadth of the ilium. 



12. Heifiht of iliac fossa.— Height of the internal iliac fossa from the superior strait to the most 

 elevated point of the iliac crest. (Upon the superior strait Verueau's point dc reph-e is situated at 

 the middle of the distance whicli separates the sacroiliac articulation from the point which cor- 

 responds to the maximum transverse diameter of the strait.) 



13. Cord of the brim.— From the sacro-iliac articulation to the symphysis pubis (at the level 

 of the superior strait). 



11. Puboischiatic depth. — The distance between the upi)er surface of the pubis and the lower 

 surface of the ischium, from the smooth level surface on the pubic side of the ilio pectineal suture 

 above to the lowest part of the tuber ischii. 



