1921 PROPLANULITIDM 41 



May 



F. Phaulomorph, or catamorph — a degenerate serpenticone. 



P. capularis, nov. Much smaller than P.Julvus, but somewhat 

 like a dwarf of it. Ribs radial, mostly trifurcate ; umbilicus fairly 

 concentric ; venter with interruption, on cast, beginning of body-ch., 

 but, at end, ribs cross strongly just before mouth : this had a raised 

 rostrum (collar) and indication of lat. auricle. Geol. Surv. Engl., 

 26081 ; Chippenham ; Kell. R., top, by decomposed condition ; Ilolo- 

 type ; S. 43, 36, 19, 39-5 ; c. 24 ribs ; body-ch., c. 5/8 wh. ; Li, c. 22 per 

 cent.; No. 26096, colomorph. this sp. ? Kellaways ; Kell. R. 



Perisphinctes cf. spirorbis ; Neumayr, 1871, Balin, xi, 4, has much 

 of characters of P. capularis ; if so, it would be a biologically earlier 

 form of this series. Ribs 23 ; F. 69, 36, 22, 38 ; Balin. 



Proplanulites haugi, Parana & Bonarelli (Call. inf. Savoie, 1895, 

 p. 157, xi, 4), does not fit into an}' of these series. It is distinguished 

 by arcuate curve of ribs on venter. Other species which have been 

 figured as Proplanulites are even more separable. 



Excluding these, 37 species of Proplanulites have been mentioned 

 by name, and some others have been referred to. Supposing the 

 existence in each series of morphic equivalents in corresponding numbers, 

 then the possible tale of species should be about 60. This number 

 seems large, but these species certainly lived during two hemera which 

 in Wiltshire are marked by considerable difference in deposit : it is 

 quite possible that they may have lived during 5 or 6 hemera; ; for the 

 lack of correspondence in the distribution of Proplanulites and Kepplerites 

 indicates a lack of synchronization, suggesting that the so-called Kella- 

 ways Clay is of more than one date. Similarly the difference in 

 distribution of Proplanulites and of Cadoceras and of Sigaloceras suggest 

 that the Kellaways Rock, or its equivalent, is a polyhemeral deposit. 



In Great Britain strata with Proplanulites-isMnsL are preserved at 

 only a few places : on the whole Continent there seems to be only about 

 as many localities showing the strata as in Great Britain — the wide 

 area of almost total destruction of Continental strata with Proplanulites- 

 fauna is thus indicated. 



Table II (p. 40) gives the presumed chronology of Proplanulites and 

 Crassiplaiuilites, interpreted from matrix, condition and similarity. 



Crassiplanulites, g. n. Genoholotype, C. crassicosta nov. 

 Comparable with Obtusicostites (p. 42), but with less developed s.l. : 

 it is intermediate between that of Obtusicostites and series A of Proplanu- 

 lites ; and with ribs curving forward towards venter, which they cross 

 in weakened condition, making a U-curve ; [later, fading away and 

 producing a smooth band]. Possible European equivalent and con- 

 temporary of Obtusicostites. Differs from Proplanulites in its massive 

 proportions, more developed s.l., EL as long as Li, Si deeper than 

 ES, greater difference between Li and L2 in size, rather more curvature 

 to secondary ribs, and the tendency to produce a smooth band between 

 primary and secondary ribs. I.i about 45 per cent, of whorl-breadth. 



Callovian, Kellaways Rock (e) ; England (Wiltshire), see Table II,- 

 p. 40. Also Russia 



C. crassicosta, nov. " Am. bakerice." Ribs stout, undulate, 

 20 primaries, mostly trifurcate ; ribs carried over periphery with a slight 

 forward sweep, and some weakening in size — the latter becomes more 

 pronounced towards end of whorl ; wholly septate ; mark of another 

 whorl ; possibly only inner part of a much larger specimen, see next 

 species. 



