12 TYPE AMMONITES— VII April 



So far the species of Maceratites are only known from the marl 

 with green grains (Inferior Oolite) of Frogden Quarry, Oborne, Dorset , 

 and the Upper White Ironshot of Dundry, Somerset, (both Sonninian, 

 Witchellia) . 



The Witchellia affinities of Maceratites are fairly obvious, and it 

 would seem to be classable as a phaulomorph of that genus or of an 

 ally. But the affinity of Pcecilomorphus may be considered quite 

 doubtful, requiring more investigation. It may be questioned whether 

 it belongs to the Sonninian or Witchellian stock at all : it may be 

 suggested that its species are anamorphs, (see T.A. hi, p. 6), phylo- 

 genetically immature examples of some quite distinct family. 



Spatulites, S. Buckman, 1928, Genotype S. spatians, T.A., vh\ 

 DCCLXV. This genus has spatulate auricles like Maceratites, and 

 from such character its name is taken. But it differs from that genus, 

 not only in proportions, but in showing a complicated Sonninian suture- 

 line instead of the simple Witchellian arrangement. 



In spatulation there is agreement with Pelekodites (T.A., iv. 

 CCCXCIX), which, however, besides being of stouter proportions, has 

 a suture-line of peculiarly plain pattern, almost too plain to belong 

 to the Witchellia group. 



In Spatulites there is a coronate stage to be detected in early whorls, 

 later the ribs are jugate on the inner margin, after the pattern of 

 Zugophorites (CCCXLI) and Zugella (DCCL) ; but in the genotype 

 Spatulites this jugate stage is short, giving way to single ribs, which 

 in the end yield to smoothness, little more than growth-lines. There 

 is a trace of septicarination, because the carina without the test shows 

 a slight indication of flattening, like the imprint of a partition-band ; 

 but in the carina itself a hollow space (infilling) would be difficult to 

 detect. 



In proportions and suture-line Spatulites would appear to be a 

 relative of Zugophorites, of which it might be regarded as a phaulomorph. 

 But, as Zugophorites is the earlier in date, this would be a case where 

 the nomomorph and the phaulomorph are not isochronous. 



Considering the rather small size of the genotype Spatulites, its 

 suture-line is more Sonninian-pattern than is that of Zugophorites, 

 which, being larger, should be more intricate than that of Spatulites. 

 The suture-line of Zugophorites is of Witchellian-pattern, somewhat 

 elaborate. The suture-line of Spatulites is of Sonninian pattern, quite 

 elaborate, allowing for small size. It is comparable with the suture-line 

 of Dundry ites. 



Dundryites, S. Buckman, 1926, (T.A., vi, PL DCLXXXVII), 

 D. albidus, holotype, a nearly smooth form ; D. pavimentarius . S.B., 

 1927, (T.A., vii, DCCLI), the costate form. The former is a well- 

 preserved specimen, with no detectable coronate stage ; there is a stage 

 of single ribs of quite low relief, which passes to a smooth (feeble 

 growth-line) stage. In general side-view the form might be mistaken 

 for a smooth development of the Witchellia-group ; but the absence 

 of a flattened venter with no indications of furrows, and the small 

 doubtfully septate carina, would arouse suspicion, confirmed by the 

 finding of a genuine Sonninian (complicated) suture-line. In regard to 

 suture-line Spatulites is in fair agreement with Dundryites, but the 

 rib-characters are not similar. 



Zugella, S.B. 1927, T.A., vii, DCCL, Genotype, Z connata, S.B., 

 Distinct from Witchellia by nearly parallel flanks and by ribs jugate 

 (connate) on edge of inner area. Shares with Zugophorites, (CCCXLI), 



