7)/'. J. W. Gregory — Egyptian Echinoidea. 155 



Genus RHYNCHOPYGUS, D'Orbigny, 1855. 

 1, Rhynchopygus Zitteli, De Loriol, 1883, 

 "Beitr. libysch. Wiiste," vol. ii, pt. 1, p. 18, pi. ii, figs. 9-11. 

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

 Coll. Geol. Surv. Egypt, ex Nos. 862, 863. 



Remarks. — The echinid referred to this species differs from the 

 type only by being slightly broader in proportion to its width. 



Genus ECHINOLAMPAS, Gray, 1825. 

 1. echinolampas tumidopetalum, n.sp. 

 Diagnosis. 



Test large and tall, subconical, rising from a level base. Seen 

 from above the shape is sub-elliptical, but the posterior half is 

 broader and fuller than the anterior part. 



Apical area and mouth subcentral. 



Ambulacra. — The petaloid portions are very swollen and upraised. 

 The inequality in the length of the poriferous zones of the antero- 

 lateral pair of petals is considerable. The petals are long, reaching 

 nearly to the margins. The poriferous zones are narrow ; the inter- 

 poriferous area is long, lanceolate. 



Floscelle well developed ; the bourrelets large and conspicuous. 

 Dimensions. 



Height 



Length 



Breadth 



Length of petal of antero -lateral ambulacrum 



Width of petal of antero -lateral ambulacrum 



"Width of poriferous zone of ditto ... 



Width of interporiferous zone of ditto 



Distance of apex from anterior margin 



Distance of mouth from anterior margin ... 



Distribution. — Miocene : Coll. Geol. Surv. Egypt, Nos. 966, 972. 



Figures. — PI. VI, Fig. la, a specimen from above ; Fig. lb, the 

 same specimen from the side : nat. size. 



Affinities. — This species is represented in the collection by 

 four specimens, of which three are somewhat broken, while the 

 fourth is a little deformed by lateral pressure. The most striking 

 character of the species is its swollen ambulacra, which are of the 

 type met with in Echinolampas stellifera, from the Caloaire Grossier. 

 From this species iJ. tumidopetalum differs by its greater size and 

 more conical test. 



Among known species of EcMnolampas this most nearly resembles 

 E. Anguillce, Cott.,^ from which it differs by the tumid petals and by 

 the more conical form of the test. The outline seen Irom above or 

 below is almost identical with Cotteau's figures 7 and 8 of his 

 West Indian species. Ecliinolampas florescens, Pom., var. coarctata,^ 



1 G. Cotteau, " Descr. Ech. tert. St. Earth, et Anguilla " : H'andl. k. Svens. 

 Vet. Akad., vol. xiii, No. 9 (1875), p. 24, pi. iv, figs. 5-8. 



2 A. Pomel, "Ech. Kef. Ighoud" : Mat. Carte geol. Algerie, ser. i, Pal. (1885), 

 p. 26, pi. iii, figs. 12-14. 



