342 G. C. Crick — On Nautilus robustus. 



Diagnosis, — Body hemisplierical ; base flattened, slightly convex 

 in middle as if for attachment. Whole surface, including base, 

 covered with a reticulating network of polygonal cells of irregular 

 shape and unequal size ; many are hexagonal or pentagonal, and 

 in one specimen (b 53) they are subequal in size. General superficial 

 appearance resembles Favosites. No internal structure known. 



Measukements. — Diameter of most perfect specimen, 30 mm.; 

 height, 17 mm. 



EXPLANATION OF PLATE XVIII. 



Fig. 1. — MonticuUpora poeulum, Salter. Wenlock Limestone : Dudley. Fletcher 

 Collection, x 1^. 

 J, 2. — A part of the same, showing longitudinal section near margin, x 10. 

 ,, 3. — A part of the same, showing spiniform and polygonal corallites. x 10. 

 J, 4. — Trachypora{?)Seeleyi, Salter. "Wenlock Limestone : Dudley. Fletcher Coll. 



X 2. 

 ,, 5. — A part of the same, x 5. 



„ 6. — Pasceolus (?) hospitalis (Salter). Middle Bala : Onny Eiver. x 1|. 

 ,, 7. — A part of the same, x 4. 

 ,, 8. — Grapfotheca catemdata, Salter. Lower Ludlow: Leintwardine. Nat. size. 



II. — Note on Nautilus mobustus, Foord & Crick. 

 By G. C. Chick, F.G.S., of the British Museum (Natural History). 



THE species Nautilus rohustiis was founded^ by Dr. Foord and 

 myself upon three examples in the British Museum col- 

 lection, bearing respectively the register numbers 37,010, 37,005, 

 and C. 1,944. 



The specimen numbered 37,010 was regarded as the type (see 

 accompanying Figures). It originally formed part of the Tesson 

 Collection, and is stated to be from the "Inferior Oolite, Les Moutiers, 

 Normandy." The horizon, however, given by us in our original 

 description, and subsequently also by Dr. Foord in his "Catalogue 

 of the Cephalopoda in the British Museum (Natural History)," 

 vol. ii, pp. 205-7, is "Upper Lias." 



The example bearing the number 37,005 belonged also to the 

 Tesson Collection, and was labelled "Nautilus inornatus, d'Orb. 

 Lias superieur, Curcy." The third specimen, which is numbered 

 C. 1,944, lacks any information as to the horizon and locality whence 

 it was obtained, but it is probably a British fossil. 



Quite recently Mr. S. S. Buckman informed me that there were 

 two examples of this species in the Cheltenham College Museum, 

 and through the kindness of the authorities of the College, to whom 

 I desire to express my sincere thanks, the specimens have been 

 sent to me for examination, so that I have been able to compare 

 them with the type-specimen. The larger specimen is labelled in 

 Mr. S. S. Buckman's handwriting, " Marlstone. Loc : unknown ; 

 but probably near Cheltenham, and possibly Alderton Hill." ^ The 



1 A. H. Foord & G. C. Crick : Ann. & Mag. Nat. Hist., ser. vi, vol. v (1890), 

 p. 271, fig. 5. 



2 Mr. Buckman tells me that this is "perhaps the Nautilus oiesus mentioned in 

 ' Geology of Cheltenham,' ed. 2, p. 40." 



