VISCERAL ANATOMY. 43 
These appear to be similar to those of S. cubanus as figured by Peters (64, Plate 
2, fig. 11), and are well ossified. The thyroid is the largest, 13 mm. in greatest 
length. It is slightly more than half a complete ring and has at the anterior 
dorsal margin on each side a process for the articulation with the tips of the 
thyrohyals. Posteriorly, the dorsal margin is similarly produced to form 
processes articulating with the postero-lateral margin of the cricoid. A low 
ridge arises about midway of the straight dorsal border and curves ventrally to 
the posterior edge. Above it on each side is a minute foramen at the dorsal 
edge of the bone. On the left side in our specimen there is in addition a mi- 
nute foramen about 2 mm. anterior to the first. The thyrohyal of each side 
has fused ventrally with the basihyal so that the three bones thus form a half 
ring, bowed back at first, then forward at the ventral side. The ceratohyals 
are appressed against the ventro-lateral margin of this ring. They are rather 
thick and about 4 mm. in dorso-ventral length. Their dorsal border, and the 
edge of the thyrohyal adjacent, articulate on each side with the epihyal, a 
broad but laterally flattened bone, that projects anteriorly from this articula- 
tion. This in turn joins with the stylohyal, which is about 2 mm. longer, and 
much more rounded and slender. It joins the skull by a very short bony proc- 
ess that projects at nearly right angles from its proximal end. This process 
may represent a fused tympanohyal. The cricoid at its anterior end is 
clasped by the converging posterior processes of the thyroid and is a complete 
bony ring, with a postero-dorsal extension. The vocal cords are attached by 
cartilage, one at each side from the anterior apex of this ring to its mid-ventral 
line, and pass forward as a delicate strand to a median attachment just back of 
the anterior edge of the thyroid. The first tracheal ring is the broadest and fits 
into the posterior end of the cricoid, to which it is bound by muscle fibers. 
Peters states that in Solenodon cubanus the first nine tracheal rings are complete 
and that there are 21 in all. In S. paradoxus the number is slightly more, 22 
to 29, and all are incomplete dorsally. The closest approximation is anteriorly 
where the two cnds of the partial rings are about 2 mm. apart. 
VISCERAL ANATOMY. 
Digestive system.— The surface of the palate is marked by transverse folds 
whose number seems commonly to be eight, omitting the ridge bounding the 
posterior end. The first is a short transverse ridge between the third incisors; 
the second is larger and passes across at about the middle of the canines; the 
