Br. J. W. Qregory — Egyptian Echinoidea. 159 



There is in the collection a specimen which, is intermediate 

 between tlie above, but nearer, if anything, to L. Esnehensis. The 

 relative dimensions are as follows : — 



Esnehensis. Aschersoni. Egypt. Surv. Coll. 

 Leugth ... .;. ... 30-42 mm. 26-37 mm. 36 mm. 



Eatio of breadth to length 1 - MO ... 1 ... 1-02 



Eatio of height to length -73 --80 ... -65 - -67 ... -74 



But the Egyptian Survey specimen has the shallow anteal notch, 

 and broader anterior ambulacrum of L. Aschersoni ; the ridge of the 

 posterior interradius is higher than in L. Aschersoni, but lower than 

 in L. Esnehensis. The apical disc of this echinid is shown on PI. VI, 

 Fig. 3. 



Distribution. — L. Esnehensis, Lor., Libyan at Gebel Ter, near 

 Esneh (De Loriol-le-Fort). L. Aschersoni, Lor., Libyan at Gebel 

 Ter, near Esneh, and west of Farafrah. 



The above-mentioned Egyptian fossil is from the Libyan Series 

 (De Loriol-le-Fort), ex Nos. 864-5. 



3. LiNTHiA CAVERNOSA, Do Loriol, 188L 



Mem. Soc. Phys. Hist. nat. Geneve, vol. xxvii, p. Ill, pi. viii, 



figs. 8-10. 

 Distribution. — Libyan Series: Gebel Omra-el-Renneiem ; El 

 Aouhi, near Edfou ; Djebel Fatira (De Loriol-le-Fort) ; Coll. Geol. 

 Surv. Egypt, ex No. 867. 



4. LiNTHiA Delanouei, Dc Loriol, 1881. 



Mem. Soc. Phys. Hist. nat. Geneve, vol. xxvii, p. 109, pi. vii, fig. 12. 

 Distribution. — Mokattam Series : Mokattam (De Loriol-le-Fort). 

 Libyan Series : Gebel Ter, near Esneh (De Loriol-le-Fort) ; 

 Coll. Geol. Surv. Egypt, ex No. 996. 



The collection includes one large, well-preserved siDecimen of this 

 species. Its dimensions are : 



mm. 



Length 60 



Breadth ... ... ... ... ... ... ... o7"5 



Height 45 



Distance of apical system from anterior margin ... ... 25 



5. LiNTHiA (?) CoTTEAUi, Toumouer, 1870. 

 Synonymy. 

 Periaster Cotteaui, Toui'nouer, 1870, " Ech. calc. a aster, sud-ouest 

 France " : Actes Soc. linn. Bord., vol. xxvii, p. 33,. 

 pi. xvii, fig. 5. 

 Linthia Cotteaui, Cotteau, 1886: "Pal. frang. Terr, tert.," vol. i, 

 Feb., p. 241, pi. Ixxv. 

 Distribution. — Mid. Eocene : Hastingues, Landes (Tournouer & 

 Cotteau). Libyan Series: Egypt; Coll. Geol. Surv. Egypt, ex 

 No. 868. 



Eemarks. — The generic position of this species seems to me 

 doubtful. The dimensions of the specimen assigned to it are as 

 follow : — 



