OCR Text |
Show 1899.] OSTEOLOGY OF THE TUBINARES. 409 A. Humerus non-pneumatic; crista inferior never inflated along its free edge. Procellariida. B. Humerus pneumatic; crista inferior inflated along its preaxial border; sub-trochanteric fossa small, receiving several pneumatic foramina. Diomedeidce, F. PELVIC LIMB. All the bones non-pneumatic; tibio-tarsus with a greatly enlarged ecto-cnemial crest forming a large flabelhform crest rising high above the articular surface ; with an extensor bridge ; outer and middle toes of equal length ; hallux more or less vestigial; tibio-tarsus with a more or less well-marked intercotylar tubercle; 1st phalanx of D. II. = to or longer than that of D. III. A. Hypotarsus complex Procellariidce. a. Tarso-metatarsus longer than the outer toe. a. Ungual phalanges flattened; basal phalanx of middle toe as long as or longer than next two taken together (Forbes). ft". Tarso-metatarsus markedly longer than the outer toe, grooved anteriorly throughout, its length = ^ that of the tibio-tarsus; ph. 1 of 1). II. longer than ph. 1, D. III. & IV Cymodroma. b". Tarso-meta'.arsus much longer than outer toe; trochlea all in same plane; grooved anteriorly, much flattened distally antero-pos-teriorly ; 3 toes nearly = ph. 1, D. II. & III., - longer than IV. Fregetta. c". Tarso-metatarsus longer than outer toe, f as long as tibio-tarsus; fibular ridge scarcely longer than the width across the proximal articular surface of the tibio-tarsus ; basal phalanges of D. II. and III. = and longer than that of IV Oceanites. d". Tarso-metatarsus much longer than the outer toe, J as long as tibio-tarsus, with a shallow groove throughout its whole length; basal phalanges D. II. and III. = and longer than IV.; outer and middle toes equal Pelagodroma. b'. Ungual phalanges pointed; basal phalanx of middle toe shorter than next two joints (Forbes). e". Tarso-metatarsus only slightly longer than the outer toe; fibular ridge obsolete Procellaria. b. Tarso-metatarsus shorter than outer toe, but much longer than femur. c'. Fibular ridge obsolescent. /". Tarso-metatarsus faintly grooved anteriorly, its outer border raised into a sharp ridge Puffinus. g". Tarso-metatarsus deeply grooved anteriorly, outer border not conspicuously developed Bulweria. a". Fibular ridge distinct. h". Tarso-metatarsal groove nearly obsolete (Daption. \ Prion. i". Tarso-metatarsus grooved anteriorly and posteriorly ... CEstrelata. i" / • it >: JJ a3. Groove deeper, length not exceeding 2^ in Majaqueus. b3. Groove shallower, length not less than 3 | iu Ossifraga. c. Tarso-metatarsus shorter than outer toe, scarcely longer than femur. k". Tarso-metatarsal groove obsolescent, hallux present. c3. Ectocnemial crest stronger; shaft of tibio-tarsus not exceeding 3^ in Thalasscuca. d3. Ectocnemial crest weaker; shaft of tibio-tarsus not exceeding 3| in Priocella. I". Tarso-metatarsal groove obsolescent; hallux absent... Pelecanoides. B. Hypotarsus simple; ectocnemial large, forming an acute angle with the entocnemial crest proximally; fibular ridge scarcely raised above half of shaft , Diomedeidce. |