Wilder.] 170 [April 6, 



Second: — The formation of a groove, the "primitive furrow," which 

 connects the cephalic and the caudal folds and indicates the posi- 

 tion of the future longitudinal axis, dividing the ovum into a right 

 and a left half. 



The membra also are left in what may be considered their neutral 

 position, extending outward at right angles with the longitudinal axis 

 of the trunk and parallel with each other; that this should also be 

 regarded as the "normal position" of the membra in contradistinc- 

 tion to their numerous "natural attitudes" will be shown hereafter. 

 This neutral position of the membra presents the convexities of the 

 knee (genu) and elbow (ancon) corresponding with the so-called 

 "dorsal" or "extensor" or " epaxial" surfaces, the manus being 

 supinated and placed flat upon the earth, and the whole armus having 

 nearly the position it has in a land tortoise or in a man when upon 

 *' all fours." 



The digits and dactyls are shown of nearly equal length ; the pre- 

 membral digit and dactyl (pollex and' primus) are joined by a dotted 

 line (A) , to represent the analogy which they undoubtedly bear to 

 each other; but the continuous line (H) unites the postarmal digit 

 (minimus) with the preskeleal dactyl (primus) to indicate the ho- 

 mology which is held to exist between them by Wyman, by Coues and 

 the writer. The carpal and tarsal bones are shown as parallel rows 

 of similar ossicles, as suggested by Wyman (55, 274). 



Omozone (shoulder girdle). 



Scutula, Lat. — * ■£,"»?, (?) Gr. — Ceinture thoracique, Foltz, 39. — 

 Schulter-gurtel, Geg., 230, fere. — Shoulder-girdle, Park., 292, fere. — 

 Scapulo-coracoid arch, Ow., 20, 184. — Hozmal arch of occipital verte- 

 bra, Ow., 63, 1, 125. — Scapular girdle, Goods., 237, 2, 199. — Scapu- 

 lar arch, Wym., 55, 260. 



Remark. For this and the following name I am indebted to Dr. 

 Coues. 



Ischizone (pelvic girdle). 

 Pelvis, Lat. — 'Iaxia, (?) Gr. — Ceinture pelvienne, Foltz, 39, fere, 

 — Beckengixrtel, Geg., 230 fere. — Hcemal arch of (?) vertebrce, Ow., 

 20, 268.— Pelvic girdle, Hum., 72, fere. —Pelvic arch, Ow., 63, 2, 307. 



Membra (the limbs). 

 Membra, Lat. — Tlbta, Gr. — Membres,extremites, Fr. — Glieder, Ger. 

 — Arlus, Bonap., Tr.Linn. Soc. 18, 248. — Legs, vulgo.— Limbs, Goods., 



