154 Dr. J. W. Gregory — Egyptian Echinoidea. 



echinids agree with S. siibrotunda (non Leske) in the length of the 

 petals, whereby they differ from the Tongrian S. striatula, Marc, 

 de Serr. They differ from the typical S. siibrotunda, Leske, by the 

 absence of the notch in the posterior margin of the test behind the 

 anus. In this character they agree with S. Paulensis, L. Ag. ; but 

 they differ from L. Agassiz's type of that form by their greater 

 equality of length and breadth. Agassiz reaiarked the close 

 resemblance of S. Paulensis and S. suhrotunda ; and it seems to me, 

 as the shape is inconstant, that the former species should be reduced 

 to a variety of the latter, characterized by the absence of the notch 

 and by the less branched actinal furrows. The branching of the 

 furrows is, however, inconstant ; they are not well marked in the 

 specimens ; but in some areas the furrows branch once as in 

 S. Paulensis, whereas in other areas there are distinct secondary 

 branches as well. 



The original locality of S. Paidensis is St. Paul-trois-Chateaux, 

 near Dax, and its horizon is Lower Miocene or Langhian.^ 



Fuchs has described two Egyptian Miocene ScutellcB. In S. 

 rostrata, Fuchs,^ from Siuah, the posterior margin is curved and not 

 truncate; and the interporiferous areas of the petals is broader 

 than in the two echinids of the Egyptian Survey collection. The 

 general shape of these specimens agrees with that of S. ammonis, 

 Fuchs, ^ in which the petals are a little shorter ; thus, the length of 

 the anterior petal is -^-5 of the distance from the inner end of the 

 petal to the anterior margin of the test, whereas the same proportion 

 in these specimens is f. 



Genus CONOCLYPEUS, L. Agassiz, 1839. 



1. CoNocLYPEUS Delanouei, De Loriol, 1881. 



Mem. Soc. Phys. Hist. nat. Geneve, vol. xxvii, p. 82, pi. ii, fig. 17. 



Var. MiLViEOKMis,* nov. 



DiSTKiBUTiON. — Libyan Series : Coll. Geol. Surv. Egypt, ex 

 No. 858. PI. VI, Fig. 2 ; two-thirds natural size. 



Remakks. — Five specimens in the collection agree in all essential 

 respects with De Loriol-le-Fort's C. Delanouei, except that the shape 

 is not elliptical but somewhat kite-shaped. The greatest width is 

 a trifle anterior to the peristome ; the sides thence run straight 

 backward, converging slightly till opposite the anterior margin of 

 the periproct ; thence they bend sharply round to the well-curved 

 posterior extremity. As De Loriol's figure (17a) is not regularly 

 elliptical, and as the test shows a tendency towards this kite-shaped 

 base, it seems unnecessary to make a new species for these echinids. 

 But the difference is so constant in the five specimens that it is 

 desirable to notice it as a varietal character. 



1 e.g. Deperet, " Classification et parallelisme du Systeme Miocene" : Bull. Soc. 

 geol. I'rance, ser. 3, vol. xxi (1893), p. 176. 



2 Fiichs, Beitr. libysch. Wiiste, vol. i (1883), p. 48, pi. xvii, figs. 4-6. 



3 Fuchs, ibid., p. 48, pi. xiv, figs. 1-4. 



* From milvus, ' a kite,' the test being kite-shaped. 



