288 SIE E. NEWTON AND DE. GADOW ON THE DODO 



sauzieri, although it is rather improbable that this species, restricted to a small island, 

 varied as much as British specimens of Strix flammea, of which latter the British 

 Museum Catalogue records the length of the '• tarsus " as 2*2 inches, i. e. 55 mm., 

 while the measurements taken from an English specimen in the Cambridge Museum 

 give the length of this bone as 60 mm. 



4. Plotus nanus, sp. nov. (Plate XXXIV. figs. 1-5.) 



The humerus, pelvis with sacrum, and tibia of the genus Plotus possess so many 

 diagnostic characters that the three bones figured on Plate XXXIV. can easily be 

 recognized as belonging to this genus of Steganopocles. 



The Humerus shows the following characteristic points : — The sulcus transversus is 

 very deep and strongly marked, extending from the tuberculum mediale halfway 

 across the head of the humerus as a groove of equal width and depth. The crista 

 superior is straight, and shows well-marked impressions of the insertions of the great 

 pectoral muscle. The supracoracoidean or subclavian muscle has an inserting surface 

 upon the corner where the caput humeri meets the proximal end of the crista superior. 

 The tuberculum inferius s. medianum is a very prominent knob, serving on its dorsal 

 and ventral surfaces for the attachments of the m. coraco-brachialis posterior and 

 m. biceps humeri respectively. The pneumatic foramen lies at the bottom of a wide 

 and deep recess. The dorsal lip of this recess is sharply marked by an oval impression 

 from the tendon of the m. scapuli-humeralis posterior (m. infraspinatus, m. teres major, 

 of other anatomists) ; from this impression the low but sharp ridge for the m. latissimus 

 dorsi is continued down the middle of the ventral or inner surface of the humerus. 

 The two grooves above and upon the ventral surface of the outer and inner condyles 

 are produced by the origins of the pronator and short flexor muscles of the forearm. 

 The m. brachialis inferior s. internus arises from a strongly maiked impression on the 

 dorsal or outer surface of the distal part of the shaft of the humerus. 



The Pelvis and Sacrum are easily referred to the genus Plotus by the deeply notched 

 or curved lateral margin of the pre-ace tabular part of the ilium, the prominent and 

 sharp antitrochanter, the sharp ventral ridge springing from the three anterior sacral 

 vertebrae, and by the position of the single primary sacral vertebra closely behind the 

 acetabular axis. The individual peculiarity of the specimen described is the lopsided 

 position of the two halves of the pelvis with reference to the sacrum. 



The Tibia is much flattened anteriorly ; its anterior or cnemial crests are high, but 

 not anchylosed with the patella ; the peroneal crest for the attachment of the fibula is 

 long and straight. The condylar portion of the tibia is turned considerably inwai'ds, 

 and the bridged-over groove for the passage of the tendon of the m. extensor digitorum 

 communis is very deep and placed obliquely. 



There remains the question of the specific differences of the bones before us. They 

 all belong, to judge from their appearance, to one adult individual, but their small 



