38 SOLENODON PARADOXUS. 
though on the ental face these lines cannot be seen. In Gymnura the sternal 
cartilages of but two ribs, the 8th and the 9th, are partly fused in this way. | 
The terminal cartilages of ribs 12, 13, 14, and 15, are bound by connective tissue 
to the posterior rim of this large fused mass in Solenodon paradorus. ‘The 
extreme development of the sternal portion of the ribs in Solenodon is very 
remarkable and apparently not found in other Insectivora. In a skeleton of 
Ericulus setosus from Madagascar, however, a somewhat similar ossification 
of the sternal portions of the ribs is present, but there is not the fusion of the 
ventral elements in the posterior members. 
The first thirteen ribs have a double articulation: by the capitellum to the 
point of union of the vertebra with the vertebra next preceding; and by the 
tuberculum to the lateral surface of the prezygapophysis. The tuberculum dis- 
appears with the fourteenth rib and the articulation is at the anterior end of the 
centrum of the respective vertebrae alone, not with the centra of two vertebrae. 
The sternum is of six pieces. The manubrium is roundly expanded an- 
teriorly. It is not keeled, but is slightly emarginate at the median extremity. 
It thus resembles that of Erinaceus and Ericulus, and differs markedly from 
that of Gymnura which is lozenge-shaped anteriorly, with a strong keel. The 
three sternal pieces following the manubrium are quadrilateral, each slightly 
longer than wide and narrower at the anterior end. The fifth piece is evidently 
a fusion of three elements, the last of which is the most reduced in width. The 
flat narrow terminal element (xiphisternum) is articulated to its dorsal posterior 
margin and bears a large oval cartilage distally. 
Compared with the sternum of Solenodon cubanus as figured and described 
by Peters, that of S. paradoxus differs notably in possessing one less element. 
There are seven sternal pieces in the former and but six in the latter. This 
difference seems clearly to be due to the complete fusion in S. paradoxus of what 
in S. cubanus are the fifth and sixth pieces, so that in the former the penultimate 
element of the sternum gives attachment to three sets of ribs instead of but two 
as in the latter. The absolute length of the articulating segments of the sternum 
is thus some 6 mm. shorter in S. paradoxus than in the Cuban species, notwith- 
standing the greater general size of the former. A second difference is found 
in the shape of the xiphioid process which in S. paradozus is simple, whereas in 
S. cubanus it is represented as of two lateral portions fused anteriorly. 
The clavicles are large and slightly sigmoid in anterior aspect. They are 
united by membrane to the antero-internal extremities of the manubrium and 
curve, dorsal to the head of the humerus, to the dorsal edge of the tip of the 
acromion. 
