chick: ox xautilus mokattamexsis, foord. 287 



the height of the wliorl was originally relatively greater. A. trans- 

 verse section of the whorl at about the middle of the fossil has 

 approximately thefollowing dimensions: height, 50 mm. ; thickness, 

 64-5 mm. ; height above preceding whorl, 31 vam. ; amount of 

 indentation by preceding whorl, 19 mm. The septa are about 18 or 

 19 mm. apart at the centre of the periphery. 



The specimen was presented to the National Collection by Sir 

 llichard Owen, and fi-om the fact that it has been labelled in 

 Dr. Henry Woodward's handwriting: " Nautilus Forhesi, d'Arch. " ; 

 it is doubtless the specimen referred to under that name by Professor 

 Owen in his paper " On the Fossil Evidence of a Sirenian Mammal 

 from the Numnuilitic Eocene of the Mokattam Cliffs, near Cairo " 

 (Quart. Journ. Geol. Soc, vol. xxxi, p. 10.'}, 1875), as may also lie 

 inferred from both Dr. Foord's reinaiks, and the fact that Dr. Foord 

 gives this reference in his synonymy of the species {op. cit., p. 329). 



Besides the type, the National Collection coTitains two other 

 examples, both internal casts, labelled by Dr. Foord " JVauiilus 

 MoJcattamensis ". One of these,' about one-half of the outer whorl of 

 an example of about 90 mm. in diameter, exhibits a portion of the 

 body-chamber, the last camera (or 'air-chamber') being only about 

 one-half of the depth of the preceding chamber, a character from 

 which it may be inferred that the shell belonged to an adult 

 individual, so that the species does not appear to have attained a large 

 size. The other sj)ecimen' in tlie collection is labelled " Egvpt ? 

 Dr. Hooker"; it Avas transferred from the Museum of Practical 

 Geology together with other foreign collections in 1880. It formed 

 part of a larger shell than either of the other two, and consists only of 

 the umbilical region, the side and part of the periplieral area of about 

 three-fourths of the outer whorl, including a small part of the bodv- 

 chamber. The umbilicus is ver)' small, and may have been closed 

 when the shell was present. The septa are relatively wider apart 

 than in the other two specimens. The fossil is preserved in a whitish 

 limestone, whilst the specimens from the Mokattam i-ange are in 

 a buff or yellowish-coloured limestone. 



In 1901 M. Cossmann ^ described and figured, under the name 

 Nautilus nubart, from the Mokattam escarpment near Cairo, a species 

 M'hich he subsequently admitted * was the same as Foord's 

 JV. mokattamensis. 



In 190G a very poor exumple and a detached septum, both from 

 tlie ^lokattam escarpment, but not from precisely tlie same localitv, 

 were figured, and referred to Foord's species, by P. Oppenheim,* who 

 supplemented Cossmann's description, at the same time pointing out 

 its resemblance to Sowerby's Nautilus imperialis. 



^ British Museum Collection, Geol. Dept., register number 83132. 

 ^ British Museum Collection, Geol. Dept., register No. C. 3403. 



* M. Cossmann, "Additions a la faune nummnlitique d'Egypte" : Bull. Inst. 



Egypt., ser. IV, no. 1, p. 174, pi. i, fig. 8, 1900 (1901). 

 ■* M. Cossmann, Bev. crit. Paleozool., vii, p. 67, 1903. 



* P. Oppenheim, Palaeontograpliica, Bd. xxx, Abth. iii, Lief. 2, p. 344, 



pi. xxvii, fig. 15, text-figure (fig. 35), 1906. 



