88b YORKSHIRE TYPE AMMONITES— II Nov. 



88. AMMONITES PEREGRINUS, Simpson 

 (Plate LXXXVIII) 



Original Description 

 4. A[mmonites] perigrinus. [M. Simpson, 1855, p. 36.] 



["I. Without a dorsal keel or furrow. 

 " a. No spines." p. 35. 1 



" A fragment with a finely rounded back equal to a semicircle, 

 then a sudden depression on the side, a flat space, and a shallow 

 umbilicus ; siphuncle well displayed, where the shell is wanting ; trans- 

 verse striae numerous, flat, in places nearly obsolete ; diameter 3 inches. 

 Mr. Ripley's collection." 



Simpson, 1855, p. [iv] "Errata in some of the copies. Page 36, 

 for perigrinus read peregrinus." P. 145, "Ammonites peregrinus." 



Additional Details 

 Simpson, 1884, p. 64, omits " Mr. Ripley's collection." 



Remarks 



Proportions : ? 61, 33, 30, 45 ; subplaty-, subpachygyral, per- 

 latumbilicate. 



Stages, conch, serpenticone ; periphery, 1 ; ornament, 2 (2c ?). 



The " depression on the side " is due to removal of test, exposing 

 cast whereon may be seen indistinctly lobes of the simple Lytoceratid 

 pattern. 



Involution must have been very little : there is only a small indenta- 

 tion. The whorl-section would be slightly obovate, but with a slight 

 inner margin. 



The genus is presumably Alocolytoceras, Hyatt, 1900 (Buckman, 

 1905, 142) ; family Lytoceratidae. 



Geological position, judging from little matrix adherent, Grey 

 Sands. The specimen is waterworn : it is presumably a fragment from 

 the interior of a larger example. 



The specimen (Whitby Museum, No. 71) bears Simpson's label 

 " A. perigrinus, Lias, Whitby Mr. R." 



Result 



Alocolytoceras ? peregrinum, Simpson sp. 1855, Yeovilian 

 [dispansum zone ? Peak], near Whitby. 





