48 TYPE AMMONITES— III July, 



1921 



breadth of whorl, L2 somewhat bifid — the outer part the larger, but 

 rather shorter]. England, Dorset, Somerset. 



M. korustes, n. Cadicone passing to sphserocone ; whorls some- 

 what galeatiform ; undulation of edge of inner margin indicates relics of 

 Tulites-stage or its costate equivalent ; umbilicus gradate, deep ; s.l. 

 with short, broad lobes, Li at 19 mm., c. 40 per cent. " Somerset ; 

 Fullers' Earth [Rock] " ; J.W.T. Coll. ; S. 44, 41, 73, 25 ; 59, 49, 79, 

 21 ; size 63 mm. ; max. c. 70. 



M. tolmerum, n. Sphaeroconic, with rather heavy ventral ribs ; 

 a less massive shell than M. sphara, with a larger umbilicus. S.B. Coll. 

 454 ; Holotype ; Laycock, Milborne Wick, Somerset ; Fullers' Earth 

 Rock (Milborne Beds) ; S. 51, 45, 63, (17 ?) ; 77, 47, 67, 16 ; max. c. 80 : 

 S.B. Coll. 2763, Paratype ; same loc, " top of F. E. Rock," confirmed 

 by condition ; S. 29, 41 '5, 65, 27-5 ; inner whorls showing a costate stage 

 analogous to that of Rugiferites ; S. 50, 46, 70, 17 ; max. c. 66 : J.W.T. 

 Coll. ; [Somerset] ; S. 47, 44, 69, i7'5 ; 67, 48, 67, 17 ; max. c. 70. 



M. sphara, S. Buckman 1920, Legend of PI. CLXVU. Asphaerocone 

 with a quite small umbilicus ; " near Sherborne, Dorset " [Milborne 

 Wick, Somerset] ; Fullers' Earth Rock [Milborne Beds] ; S.B., ex J.B., 

 Coll.,, 1923 ; Holotype ; S. 65, 48, 69-5, — ; 99, 51, 66, 10 ; max. c. 105. 



M. homceoticum, n. The homceomorph of Am. morrisi, Oppel, 

 see sub Morrisites : it is distinguished by a slight difference of ribbing, 

 by an umbilicus not gradate and not undercut, by suture-line. Sub- 

 sphaeroconic, with a quite small umbilicus, and a suggestion of its opening 

 out again. S.B., ex J.B., Coll. 2758, Holotype; S. 74, .50, 64, — ; 

 91, 48-5, 59, 12 ; max. c. 105 ; s.l. with short, broad lobes, Li at 29 mm., 

 c. 38 per cent. : S.B. Coll. 2757, Paratype ; Milborne Wick, Som. ; 

 " F.E.R. Top " (Milborne Beds), near surface by condition ; S. 45, 49, 

 54, (17 ?) ; 69, 52, 63, 12. 



M. comma, n. A scaphitoid ; passing frem sphaerocone to 

 incipient serpen ticone ; a quite small umbilicus rapidly opens out, has 

 a comma-like appearance ; smooth stage attained ; s.l. decidedly 

 degenerate, with quite short, broad lobes, Li at 25 mm., 24 per cent. ; 

 J.W.T. Coll., Holotype ; Shepton Montague, Somerset ; F. E. Rock 

 (Milborne Beds) ; S. 51, 50-5, 69-5 (4 ?) ; 91, 40, 45, 23 ; max. c. 95 ; 

 body-chamber nearly complete, end showing tendency to renewed 

 inflation. 



M. sknipum, n. Much compressed, with a quite small umbilicus. 

 Like M. comma, but much thinner in costate stage (presumed smooth 

 stage not preserved). S.B., ex Darell, Coll. 2759, Holotype ; Milborne 

 Wick, Somerset ; Fullers' Earth Rock, [Milborne Beds, near surface by 

 condition] ; S. 62, 48, 53, 15. 



Morrisites, g. n. (Slephanoceras, Macrocephalites, Auctt.) ; 

 Genotype, A. morrisi, Oppel, Geol. Surv. Engl. Coll. 25617. Like 

 Morrisiceras, with, presumably, similar evolution ; differs internally by 

 more elaborate s.l., externally by finer, more numerous ribbing, undercut 

 umbilical wall and suspicion of constrictions ; s.l. with lobes somewhat 

 long and narrow, EL. about 75, and Li about 55 per cent, of whorl- 

 breadth ; L2 in two branches, with a deep incision. England, Gloucester- 

 shire ; Dorset : Germany, Baden (Schlippe), perhaps ; see later, p. 49. 



M. fornicatus, n. Like Morrisiceras korustes, but with smaller, 

 more numerous ribbing ; whorls in arch-form {fornicatus), but not quite 

 so strong as those of M. korustes ; S.B., ex J.B., Coll. 2761, Holotype ; 

 marked " Sh." - Sherborne, Dorset, possibly some part of the Fullers' 

 Earth Rock outcrop running S. of Sherborne ; matrix grey, hard, some- 



