1901.] ANATOMl' OF GRUirORM IJIIIDS. 649 



slight degree of apocentricity is shown by the diastataxic Eury- 

 pygidae. The apocentric loss of one division or the other is shown 

 by the remaining groups, eutaxic or diastataxic ; while diastataxic 

 Cranes may show the final apocentricity of complete loss of both 

 divisions, and by individuals at least of the eutaxic Dicholophidae. 

 Caud-ilio-flexorius (semitendinosus and accessory semitendinosiis). 

 Ischio-fteasorius. Gastrocnemius, middle ov posterior-femoral head. — 

 In all the Gruiformes the two first-mentioned constituents of this 

 muscle-complex are present and have a similar origin and general 

 course. The caud-ilio-flexorius (text-figs.? 79 & 80, CAUD.-IL.- 

 FLEX.) arises from the distal surface of the ilium, distal and super- 

 ficial to the iliac portion of the caud-ilio-femoralis, and with a 

 varying extension to the lateral fasciae over the tail. It lies superficial 

 to the caudal portion of the origin of the caud-ilio-femoralis when 

 that is developed, and at its origin it may be forked to allow the 

 passage of that muscle. The ischio-flexorius arises from the 

 distal and lateral surface of the ischium, and runs nearly parallel 

 with the caud-ilio-flexorius, but separated trom it by the caud-ilio- 

 femoralis when that is present. The insertions and relations 

 with the gastrocnemius show considerable differences among the 

 Grruiformes, but these fall readily into four types : — 



(1) Ralline tj-^e. In Eallus longirostris (text-&g. 81) — and the 

 other Rails examined are similar — the caud-ilio-flexorius has a 

 well-marked and broad insertion to the distal end of the femur 

 (accessory semi-tendinosus, G.I.L. 1 in the figure), the fibres of 

 which meet at an angle with the fibres coming from the iliac origin, 

 foruiing a tendinous raphe. This tendon, and with it a good body 

 of muscular fibres, runs distally to join the tibial head of the 

 gastrocnemius. The junction occupies the position of the usual 

 ]3o.sterior femoral or middle head of the gastrocnemius, but this 

 head either is absent or is indistinguishably fused with the 

 femoral insertion of the caud-ilio-flexorius. Moreover, a well- 

 marked flat tendon (text-fig. 81, A. 1) runs straight to the tibia 

 from the proximal portion of the raphe, independent of and 

 partly under the larger flat tendon (text-fig. 81, A. 3) by which 

 the ischio-flexorius is inserted in normal fashion to the tibia. 

 From the proximal portion of the tendon of the ischio-flexorius a 

 stout branch is given oft: to the gastrocnemius, meeting that muscle 

 near the similar branch from the caud-ilio-flexorius. 



(2) Aramus type. This type (text-fig. 82) may be described most 

 simply as a modification of the Ralliue type, differing from that 

 chiefiy in two points : the femoral insertion of the caud-ilio- 

 flexorius {C.I.L. i) is equally broad, but is immediately superficial 

 to a well-marked posterior femoral head of the gastrocnemius. 

 This is shown in the figure at Gc. 2, a portion of the caud-ilio- 

 flexorius being represented as cut away. The two join the tibial 

 head of the gastrocnemius together, almost at the same point as 

 the gastrocnemial insertion of the ischio-flexorius, but the ar- 

 rangement is such that the latter muscle might be described as 

 joining the tibial head of the gastrocnemius superficial to the 



