80 
This genus, however, as well as being generally more evolute, 
shows a different ontogeny (see Zaborski 1987: 43 for a 
discussion). Its juvenile whorls characteristically show strong 
ribs arising in twos or threes from umbilical tubercles, elements 
of this ornament persisting to varying stages in later ontogeny. 
The present material shows an ontogenetic development typical 
of Vascoceras rather than Fagesia. 
Barber (1957) proposed two species of Fagesia from 
north-eastern Nigeria but pointed out that they were both 
intermediate with Vascoceras. These forms are problematical, 
being based on a very few specimens of unknown stratigraphical 
provenance. F. simplex Barber (1957: 27, pl. 8, fig. 1; pl. 29, figs 4, 
5) has a simple suture and is best regarded as an indeterminate 
Vascoceras. F. involuta Barber (1957: 27, pl. 9, fig. 3; pl. 29, figs 6, 
7) has a complex suture, narrow umbilicus and highly depressed 
whorls; the early growth stages are unknown. It may be most 
closely related to V. globosum globosum. 
Vascoceras globosum proprium (Reyment, 19545) 
Figs 45-47, 49, 55—57, 63, 64 
1920  Vascoceras angermanni Bose: 217, pl. 16, figs 1, 3 
(only); pl. 17, fig. 1. 
1920 Neoptychites aff. cephalotus (Courtiller); Bose: 221, pl. 
18, figs 3, 10, 13. 
1931  Thomasites sp. Adkins: 56, pl. 2, figs 16, 17. 
1954b Pachyvascoceras proprium Reyment: 258, pl. 5, figs la, 
b; text-fig. 3d. 
1954b Pachyvascoceras proprium plenum Reyment: 258, pl. 5, 
fig. 5; text-figs 3c, 6. 
1954b Gombeoceras? bulbosum Reyment: 263, pl. 4, figs 2a, b; 
Fig. 49 Sutures in Vascoceras globosum proprium (Reyment). A, C.93550 at a diameter of 40 mm. B, C.93906 at a diameter of 54 mm. C, C.93905 at 
a diameter of 18 mm. D, C.93904 at a diameter of 30 mm. E, C.93549 at a diameter of 38 mm. All specimens from the Pindiga Formation, unit T2, 
Ashaka. 
21957 
1957 
1957 
1957 
1957 
1963 
1963 
1978 
1982 
1982 
1987 
1989 
1989 
1992 
MATERIAL AND OCCURRENCE. Eleven specimens, C.93365, 
P.M.P. ZABORSK] 
text-figs 3g, 9. 
Vascoceras ellipticum Barber: 17 (pars), pl. 6, figs la, b: 
pl. 26, fig. 11 (only). 
Vascoceras globosum globosum (Reyment) Barber: 21 
(pars), pl. 7, fig. 1. 
Vascoceras globosum plenum (Reyment) Barber: 23, pl. 
7, fig. 2; pl. 9, fig. 2; pl. 28, figs 3—S. 
Vascoceras globosum proprium (Reyment) Barber: 25, 
pl. 7, fig. 3; pl. 28, figs 6, 7. 
Vascoceras globosum compressum Barber: 25, pl. 7, fig. 
4; pl. 9, fig. 1; pl. 28, figs 10, 11. 
Pachyvascoceras compressum (Barber) Powell: 321, pl. 
32, figs 2-4, 7; pl. 34, figs 8, 10; text-figs 3b—d, f. 
Pachyvascoceras globosum Reyment; Powell: 321, pl. 
34, figs 7, 11; text-fig. 3s. 
Paravascoceras carteri (Barber); Chancellor, Reyment 
& Tait: 92, figs 15-17. 
Paravascoceras carteri (Barber); Chancellor: 102, figs 
35-37. 
Paravascoceras compressum (Powell 
Chancellor: 106, figs 49, 50. 
Vascoceras proprium (Reyment); Kennedy, Wright & 
Hancock: 46, pl. 4, figs 1-15, 18, 19; pls 5, 6; text-figs 
8A-C, 9. | 
Vascoceras  (Vascoceras) proprium  (Reyment);): 
Kennedy, Cobban, Hancock & Hook: 80, figs 20A, B. 
Vascoceras sp. juv. indet. Meister: pl. 11, fig. 3. 
Vascoceras sp. aff. obscurum Barber; Courville: pl. 10, 
fig. 2 (only). 
not Barber) 
L_5 mm_4 
