

1921 PROPLANULITIDM . 35 



P. sp. P. subcuneatus, Teiss., iv, 13a, v, 13 b, c, seems from its 

 subelaborate si., Li at 2i'5 est., 34 per cent., to belong to this series. 



A. 4. Venter subgibbous, crossed by ribs ; a, secondary ribs curved. 



P. curvus, nov. . Ammonites koenigii ; Brauns, Jura nordwest. 

 Deutschl., 1869, p. 133 ; PI. I, f. 1 ; Porta Westphalica ; Macrocephalen- 

 schichten ; Holotype. Like P. opimus, but with a regularly concentric 

 umbilicus. T. go, 40, 26-5, 3i - 5. 



P. opimus, nov. Like P. arcigura [arciruga] ; Tornquist, 1894, 

 xlvi, 2, and like P. koenigi, Sow. sp. ; but ribs incline more forward 

 and pass over venter ; si. is well developed. Primaries 17, mostly 

 trifurcate, one intercalate usually ; ribs [in young, fairly radial], later 

 bending more and more forward, passing over venter, somewhat 

 weakened, making a slight U-curve. Geol. Surv. Engl., 26085, Chippen- 

 ham, Wilts ; Kell. Rock (d) ; Holotype ; S. 55, 40, 30, 30 ; 85, 40, 29, 

 32 ; max. c. 130 ; Li at 25, 38 per cent. No. 26095, Id. ; S. 65, 40, 

 31-5, 32 ; Li at 20-5, 36-5. 



A. 4, b. Secondary ribs nearly straight. 



P. tornquisti, nov. P. koenigii ; Tornquist, 1894, p. 552 ; xliv, i, 

 Holotype ; Pourcandes, Mezieres (Ardennes), France ; Callovian ; F. no, 



37, 33. 38 ; Li at 29-5, 34 per cent. ; 19 ribs. 



P. sp. P. arcigura {arciruga} ; Tornquist, 1894, xlvi, 2 ; Chippen- 

 ham, Wilts ; F. 43, 37, 31, 35 ; F. 80, 36-5, 29, 32-5 ; " T. 70, 38, 30, 35, 

 size 80," p. 568. G.S.E. No. 26100 ; S. 46, 39, 30-5, 30-5 ; No. 26098 ; 

 S. 39, 42, 32, 29-5 ; both Chippenham, Kell. R. (d), associate better here 

 than with P. opimus. 



P. cracoviensis, Tornquist, 1894, p. 558. Name given to P. koenighi, 

 Teisseyre 1887, (Pam. Ak. Krak. XIV, iv, 1, 2, v, 1, 3, 4). These are 

 syntypes. Take as lectotype, iv, 1. Fig. lb shows ribs crossing venter 

 more plainly than in P. koenigi (Sow.), agreeing with the A. 4 series. 

 The only difficulty is its ? si. — Li (fig. id) works out to no more than 

 31 per cent. ; but that of his v, 3b, is 37 per cent. 



If the identification of P. koenighi, Teiss., as morphic equiv. of 

 P. koenigi (Sow.) and a member of the present series be correct, it means 

 that this series is the typical one for Proplanulites. Czerna ; F. (ia, b) 

 59, 41-5, 30-5, 29 ; F. (ic) 53, 42, 33, 30 ; 18 ribs ; genoholotype. 



P. sp., P. konighi, Neum., Balin, xi, 3. Like next stage to 

 P. Iczvigatus, widening of umbilicus beginning earlier ; Balin ; F. 83, 

 38-5, 28, 31 ; 16 ribs, radial. Thickness seems too great, and ribs are 

 depicted crossing venter ; both characters are against association with 

 P. IcBvigatus ; but make it a possible terminal of this series. 



B. Nomomorphs ; si. subsimple, c. 30 per cent. 1. Venter sub- 

 cuneate. 



P. polonicus, nov., P. arciruga, Teiss. iv, 8, v, 8, Filipowice, 

 Poland ; Holotype (non Teiss., iv, 5) ; F. 50, 37, 26, 34 ; 20 ribs ; F. 73, 



38, 26, 34 ; 22 ribs ; Li at 20-5 mm. est., 31-5 per cent. Geol. Surv. Engl., 

 No. 7693 ; Rampisham, Dorset ; K. Clay (a) ; a brephomorph ; paratype ; 

 S. 47'5, 37, 24, 34 ; 18 ribs ; Li at 13 mm., 31 per cent. 



P. OCCUltuS, nov. Morphic equiv. of P. Icevigatus, but with more 

 and smaller ribs — 18 to 78 mm. diam. — and less developed si. Geol. 

 Surv. Engl., ex Hudleston Coll., No. 30775 ; Rodborne, Malmesbury, 

 Wilts ; Kell. Clay (a) ; inner whorls and part of outer, wholly septate ; 

 S. 70, 41-5, 28, 27-5 ; 158, 39, 23-5, 30 ; Li at 31 mm., 31 per cent., 

 at 59 mm. 30 ; max. c. 290 +. 



P. latus, nov. Like P. koenighi, Teiss, iv, 1, but thinner, and 

 with smaller, narrower ribs ; like P. subcuneatus, Teiss., iv, n, but with 



