GEITEEA. AND aEOUPS OF THE ECHINOIDEA. 255 



of Agassiz would not have much difficulty in believing that if he 

 had known that there was a subanal fasciole present, he would have 

 regarded the species as one of a group of Eupatagus. Dames, in 

 considering an Eocene Peripneustes, noticed how close the form 

 was to Eupatagus, and if E. avellana from Sind is examined 

 the alliance is evident. There is, however, the question about 

 the taxoaomic value of flush and grooved ambulacra. This is to 

 a certain extent answered, because there are forms intermediate 

 between the perfectly flush broad ambulacra of JEupatagus and 

 the grooved ambulacra of Peripneustes, and the Sindian species 

 Macropneustes speciosus and Eupatagus avellana are intermediate 

 to a certain extent . 



It is proposed to make Macropneustes and Peripneustes syno- 

 nymous, as Cotteau has done, and to place the first as a subgenus 

 of Eupatagus {Euspatangus). The diagnosis of the subgenus will 

 have to receive the addition of "a subanal fasciole, and the 

 ambulacra semiflush or in grooves." 



This will place A. Agassiz' s recent Macropneustes spatangoides, 

 1883, ' Blake ' Echiui, p. 64, in a subgenus of Eupatagus. 



There remain a considerable number of species which were pro- 

 perly considered to belong to Macropneustes, Agassiz, 1847 (not 

 in reference to the type-species). Most have more or less flush 

 ambulacral petals, and rather large tubercles within the peri- 

 petalous fasciole. They must enter Hypsopatagus, Pomel, 1883 

 (see ante, p. 239). 



Peripneustes was founded by Cotteau, 1875, Kongl. Svensk. 

 Vet.-Akad. Handl. Bd. xiii. No. 6, p. 38, pi. vii. ; and considered 

 by Dames, 1877, Palseontographica, xxv., Ech. Vic. Tert. p. 73 ; 

 Duncan & Sladen,1883, Pal. Ind. ser. xiv. Ech. Kachh & Kattywar, 

 p. 41. Trachypatagus, Pomel, 1883, Theses, p. 31, is a synonym. 



Subgenus Maceopneustes, Agassiz (genus), 1847, Gatal. Pais., 

 Ann. d. Sci. Nat. ser. 3, vol. viii. p. 8. (Figure of the typical 

 species, vol. vi. pi. xvi. figs. 2, 2a.) (Pars.) {Enlarged.) 

 Syn. Peripneustes, Cotteau, 1875. Trachypatagus, Pomel, 1883. 

 Stomaporus, Cott.l^'d^,. Isopneustes, Vomel? 



Test thick, tumid ; ambulacral petals elongate or broad, grooved 

 or semiflush, open or imperfectly closed ; poriferous zones 

 equalling the interporiferous area in breadth. Tubercles large, 

 upon the interradial areas, but less projecting than the tubercles 



