5!) 



tribe present those peculiar modifications of tlie distal trochlese, wdth 

 the strong articulation for the back toe, which relate to the scan- 

 sorial modifications of the bird's foot ; and the Penguins associate 

 with their broad and short metatarse a characteristic retention of 

 much of the primitive separation of the three constituent bones. In 

 the Dinomis elephantopus these elements have become as completely 

 coalesced as in any other species, and the general chavacters of both 

 proximal and distal ends aceord with those in previously described 

 species. On a more special comparison of the metatarse of the 

 Dinomis elephantopus with that of its nearest congener, the Dinomis 

 c}'assus, the following differences present themselves : — The ento- 

 condyloid depression is deeper, its fore-and-aft diameter is greater, 

 and its transverse diameter less, than in the ectocondyloid one ; but 

 the breadth of the entocondyloid depression is relatively greater, and 

 its depth somewhat less in the Dinomis elephantopus than in the 

 Dinomis crassus. The transverse convexity dividing the two con- 

 dyloid depressions is relatively broader in the Dinomis elephantopus ; 

 and the rough surface external to the anterior intercondyloid pro- 

 minence is more strongly marked. The two calcaneal ridges present 

 an eqnal prominence in Dinomis elephantopus ; the ectocalcaneal 

 one is the more prominent in Dinomis crassus. The anterior surface 

 of the metatarse differs chiefly in the proportions indicated in the 

 table of admeasurements from that in the Dinomis crassus ; likę 

 most of the metatarses of that species, one or more vascular foramina 

 oceur above the subcircular rough surface of iusertion of the flexor 

 pedis, which occupies the lower part of the shal]ow depression in 

 the upper and fore part of the shaft. Along the lower half of the 

 shaft, the median longitudinal, and progressively widening pro- 

 minence, due to the middle of the coalesced metatarsal bones, is 

 rather more marked than in Dinomis crassus. The inner side of 

 the shaft is marked at its upper half by the obliąue rough tract 

 indicative of the insertion of the powerful aponeurosis of the gastro- 

 enemii museles. At the back surface the upper part of the middle 

 metatarsal is relatively less prominent than in Dinomis crassus. 

 The two vascular foramina occupy corresponding relative positions. 

 Ali other notable differences are those of size and proportion. 



From the metatarse of the Dinomis robustus that of the Dinomis 

 elephantopus differs most strikingly in its proportions of length to 

 breadth, being little more than half the length, but of nearly equal 

 breadth ; the distant trochlese, however, being relatively less ex- 

 panded than in the Dinomis robustus. 



The anterior vascular perforation is less than in the Dinomis ro- 

 bustus ; the insertional roughness for the tibialis anticus below the 

 foramen is of equal size. The upper half of the fore part of the 

 metatarse of the Dinomis robustus is longitudinally channeled in the 

 Dinomis robustus, not in the Dinomis elephantopus. The corre- 

 sponding part of the back part of the shaft is much more prominent 

 in the Diliomis robustus. The characteristics of the metatarse of 

 the Dinoriiis elephantopus are more strongly manifested in the 

 comparison with that of the Dinomis giganteus, of which bone 



