44 TYPE AMMONITES— III July 



species from two different matrices (two horizons) " — S. Buckman, 

 Brach. Namyau Beds ; Pal. Ind. ni (2), 1918, 235. The two specimens 

 are in the Museum of the Geological Survey of England, numbered 

 25610 and 25615. The first, which is mainly depicted (reduced x 079) 

 in fig. 1, and has the aperture preserved, is from the Shelly Beds of 

 Minchinhampton — a creamy coloured limestone with shell fragments 

 and many small white oolitic grains : it bears the original label in 

 Lycett's handwriting, " A. subcontract us, M. & L. Gr. Ool. M — hampton." 

 The second specimen is a much larger shell, with a depressed aperture : 

 the general shape of the specimen is represented in fig. la, but the 

 apertural edge is taken from the small example. The large specimen 

 is from a hard, fawn-coloured, non-oolitic limestone, presumably an 

 earlier deposit than the Shelly Beds, but it does not seem quite to fit 

 the descriptions either of the Weatherstones or of the Basement Bed 

 (Lycett, Cotteswold Hills, 1857, p. 94). 



In their description (p. 11) of Ammonites subcontractus Morris & 

 Lycett give the dimensions of the large specimen — " Diameter, 5 inches. 

 Thickness, 3 inches. Height of aperture, i£ inches." These figures 

 will read as T.127, 30, 60, — ; their fig. i« yields F. 68, 31, 53, — ; and 

 the large specimen gives S. 123, 36, 57, 33. Their fig. 1 yields F. 68, 

 32'5, — •, 41 ; the small specimen gives S. 86, 35, 51, 35 — both figure 

 and specimen being measured a little behind the aperture, which con- 

 tracts rather suddenly. It may, therefore, be seen that though the 

 authors say " the specimen from which our figure is taken," the illustra- 

 tions 1 and xa are really synthetographs — fig. 1, in tfye main, fits the 

 small specimen ; but the height of the aperture has been reduced under 

 the influence of the large example ; while fig. la fits the large example, 

 but the apertural margin is put in from the small specimen. Of the 

 description, the main part fits the small shell, but the dimensions are 

 those of the large one. The remark, " proportion of umbilicus to diameter 

 rather more than one-half," is incorrect, even if taken from upper edges 

 instead of from contact-lines. The umbilicus of the small specimen is 

 only partially excavated, not so much as is depicted in fig. 1 ; while 

 that of the large example had not been excavated at all. The facts 

 pertaining to the figures and descriptions make it necessary to treat the 

 two specimens as syntypes. As the small example shows the " sub- 

 contract " character more plainly than the large one, because it has the 

 mouth complete, it is chosen as the lectotype. 



Morris & Lycett attribute the feebleness of ornament to the 

 process of clearing away the original matrix. This is not the case : 

 the small specimen shows some signs of abrasion before entombment, 

 the large specimen does not. Ornament of very feeble relief passing to 

 complete smoothness is a character of the 'Tulitids. 



Tulites, g. n. (Stephanoceras, Cceloceras Auctt.). Genotype, T. 

 tula, n. Cadicones of Erymnoceras aspect, with funnel-shaped (crater- 

 like) umbilicus, walls almost superimposed, only feeble gradation ; 

 walls of umbilicus make a sharp junction with venter, and carry bullae 

 of low relief ; an earlier stage — primary costse ending with short spines 

 (Teloceratan) seems to be indicated. S.l. with short, narrow L2 and 

 small aux. 2, the latter turned towards venter (askew) : cf. Siemiradzki's 

 fig. cit. sub T. cadus. Distinguished from Erymnoceras by feebler 

 ornament and by ribs curving forward over venter, also by suture-line. 

 There is reason to conclude that Siemiradzki's figure of s.l. is taken from 

 an example of T. cadus, and represents the s.l. of this genus : only the 

 inner part observable in genotype. England ; Lithuania. 



