METOICOCERATID. 115 
Locality: St Croix. 
Age; Cenomanian. 
MANTELLICERAS VICINALE (Stoliczka). 
Ammonites vicinalis Stoliczka, 1865, Foss. Ceph. Cret. Southern India, pl. 44. 
Locality: India. 
MANTELLICERAS UsHAS (Stoliczka). 
Ammonites ushas Stoliczka, 1865, op. cit., pl. 51. 
Locality: Xndia. 
MANTELLICERAS INDIANENSE Hyatt. 
Ammonites mantelli Stoliczka, 1865, op. cit., pl. 41, 42. 
This species is similar to true mantelli, but the shell retains the eight 
rows of tubercles and the facetted form until a much later age. It finally 
loses these larval characters and takes on the usual aspect, with only two 
rows of ventral tubercles and compressed volutions. There are probably 
two species under this name. The type of this is fig. 1, pl. 42, a more 
ornate shell than any variety of mantelli, with larger tubercles and deeper 
depressions on the venter. ‘ 
MANTELLICERAS DOMEYKANUM (Bayle and Coquand). 
Ammonites domeykanus Bayle and Coquand, Foss. sécondaires rec. dans le Chili, 
ete., p. 10, pl. 2; figs. 2-5. 
Retains the tuberculate stage until quite large, and in the full-grown 
shell, which is of great size, the last volution being 80 and 90 mm. in 
diameter in one specimen, there are still six lines of well-developed 
tubercles and the subquadrate form of the volution is but little modified 
This is by far the most primitive form of this group. 
METOICOCERATIDA: Hyatt. 
This family is necessarily instituted for a peculiar group of species 
whose development does not admit them within the pale of either Heinzide 
or Pulchellide,- but whose later stages show that they belong in the same 
group with the latter. The family and generic and to some extent specific 
characters are necessarily mingled in the following descriptions: 
