92 ZIPHIUS CAVIROSTRIS ON THE QUEENSLAND COAST. 
bones are present. When compared with the interesting 
series figured by True, they are found to agree best with 
No. 4, which is the type of Z. grebnitzkii. In one periotic 
the fenestra ovalis was closed by a simple rod of bone 
representing the stapes. 
Mandible.—The rami of the mandible are not anchy- 
losed. The superior contours agree well with figure 1 in 
Plate 22 of F. W. True’s work on the Ziphiidae.* The 
alveolus terminating the right side has an’ open groove 
anteriorly, but this may be abnormal; unfortunately the 
corresponding portion of the left ramus is broken, and 
cannot be compared. The single tooth forwarded is 51mm. 
in length. It tapers from a basal diameter of 12 mm. 
to an acuminate enamelled tip. In section it is sub-cir- 
cular ; the root is hollow and the cavity extends to within 
12 mm. of the tip. When placed in the alveolus only the 
tip protrudes. 
In certain characters, notably the small conical tooth, 
the absence of a mesorostral ossification and of a pronounced 
prenarial basin, our specimen exhibits the characters of an 
immature female. 
F. W. True has shown that Ziphius gervaisii (Duvernoy) 
represents a female of Z. cavirostris, and Dr. 8. F. Harmer 
also accepts this principle of sexual diagnosis (loc. cit.), 
so there is sound reason for classifying these remains as a 
female of Cuvier’s species. So long ago as 1870, Owen 
referred to the small size of the mandibular teeth as typify- 
ing a female. 
No actual measurements were taken by the discoverers, 
but the specimen when first stranded is said to have been 
“about nineteen feet.’ 
Dimensions of Cranium and Mandible :— 
Total length of cranium a es 5c or 830mm 
Maximum breadth (between zygomatic processes 
of the squamosal) Be 467mm 
Maximum height (from inferior bodes of ptaryaente 
to vertex) .. we nie 414mm 
Distance from tip of rata We poston median 
margin of pterygoids .. Se ie ee 636mm 
*True, Bull. 73, United States Nat. Mus., 1910. 
+Owen, Mon. Brit. Foss. Cretacea, No. 1, 1870, p. 12. 
