152 INFERIOR OOLITE AMMONITES. 



two views of a very well-preserved specimea of this species from Coaley Wood, 

 which help to elucidate the poorer type-specimen. 



In Plate XXIV is depicted the side view of a magnificent adult specimen, 

 which I obtained at Coaley Wood on the top of Bed 16. This giant specimen has 

 all its test on this side in good and complete preservation ; and it shows, round a 

 considerable portion of its whorl, the large trenchant carina. Plate XXV, fig. 1, 

 gives the front view. 



Plate XXVIII, figs. 1, 2, exhibit the inner whorls extracted from a large specimen 

 of this species. The figures are of natural size and the top of fig. 2 gives just an 

 indication of a keel ; but no ribs are visible. Fig. 3 shows the suture-line taken 

 from the same specimen, but considerably enlarged. Plate XXVI, fig. 6, gives an 

 outline of the termination taken from a broken specimen; the arrow points 

 towards the centre of the specimen. In Plate A, fig. 35, the suture-line, taken 

 from a medium-sized specimen of this species, is depicted. 



Haugia Dumortieei, S. Buchnan. Plate XXIII, figs. 16, 17 ; Plate A, fig. 36 



(under the incorrect name of Haugia 

 Ogerieni^). 



Discoidal, compressed, hollo w-carinate. Whorls elliptical, ornamented with 

 subsigmoidal ribs moderately projected on the ventral area and springing from a 

 few ill-defined tubercles on the inner margin. Ventral area not defined, carrying 

 a rather small hollow carina. Inner margin sloping, smooth. Inclusion two- 

 thirds ; umbilicus small and deep, quite smooth in the middle. Suture-line 

 (Plate A, fig. 36) possesses an inferior lateral lobe larger than is usual in the 

 genus, and two small auxiliary lobes. 



The ribs turned so distinctly towards the front and the carina smaller than in 

 the other species of Haugia and not laterally sulcated, — these are the features 

 which seemed to agree so exactly with Dumortier's description of his Am. Ogerieni 

 that I mistook this species for it. Now I see that, although Haugia jugosa {Ogerieni) 

 possesses these characters separating it from H. variabilis, yet this species 

 possesses the same characters much more strongly marked. In particular the 

 much smaller carina separates it from H. jugosa (compare Plate XXIII, figs. 14 

 and 16), while the ribs not only possess a much stronger forward sweep, but have 

 on the lateral area a slight bend which gives them a subsigmoidal, instead of a sub- 

 arcuate, appearance. Furthermore the species possesses a smaller umbilicus, and 

 is, if anything, rather thicker ; while its tubercles are much less distinct. 



' The reader is requested to alter the explanation of these plates in accordance ^\ith the above. 



