14 Prof. P. Martin Duncan — On Galerites albogalerus, LamTc. 



as a sub-order intermediate between the Echini proper and the 

 Clypeastroids.'" That is, between the groups with teeth. A. Agassiz 

 has not otherwise remarked upon the genus. 



In 1874 the Pal£eontographical Society ^ published a Monograph 

 on the British Fossil Echinodermata from the Cretaceous Formations, 

 by Dr. T. Wright, F.R.S., etc.^ It dealt with the genus Echinoconus, 

 Breynius, and described Galerites albogalerus under the name of 

 Echinoconus conicus.^ In the generic diagnosis * Dr. Wright states 

 that the peristome is " notched " with internal auricles supporting a 

 ^pentagonal masticating apparatus. He observes also that the pores 

 are unigeminal except near the peristome where they are trigeminal, 

 moreover that there are miliary granules either microscopic and 

 homogeneous filling up all the intermediate spaces between the per- 

 forate and crenulate large tubercles, or larger and more developed and 

 disposed in regular circles around the primary tubercles. He states 

 that there axe five ovarial [genital) plates, one being imperforate, and 

 "the right antero-lateral is much the largest and is prolonged pos- 

 teriorly with a portion of the madreiDoriform body into the centre of 

 the disk ; the three other plates are much smaller and terminate 

 externally in prominent angles in which the genital aperture is 

 pierced. The five ocular plates are very small and interposed between 

 the angles of the ovarials. Dr. Wright describes the form now under 

 consideration as the most typical of the genus. The diagnosis is as 

 follows : " Test much elevated, conoidal, larger anteriorly than pos- 

 teriorly ; slightly angular and rounded at the border; base flat; 

 single inter-ambulacrum tumid and recurved ; vent large, oval, irfra- 

 marginal; mouth opening central, peristome decagonal, armed loith 

 five pairs of deniigerous jaws ; ambulacra straight, narrow, doubly 

 lanceolate ; pores small, unigeminal in oblique pairs, which become 

 trigeminal near the peristome ; inter-ambulacre wide, angular ; 

 tubercles on both areas, small, homogeneous ; granules abundant, 

 unequal, sometimes elongated and prominent ; apical disk small, 

 quadrangular, very solid. Height, 1 iV iiich ; altitude, 1 --ro inch. 



The .species is illustrated on plate 1 of the Monograph on the 

 British Fossil Echinodermata from the Cretaceous Formations, vol. i. 

 part 6, Pal. Soc. Lond., 1874. The apical disk shows the fifth 

 genital plate and the very wide apart posterior ocular plates (fig. Ic). 

 The ambulacrum drawn shows rectangular equal plates and slightly 

 oblique pores. The figure 8 is said to exhibit the jaws and teeth in 

 situ, and figure 6, a copy from Forbes, shows the teeth magnified. 



The species is very common, and yet the majority of specimens 

 do not show structure well, but the British Museum contains many 

 which are beautifully preserved, and amongst them the celebrated 

 Bowerbank type. I have a few perfect specimens, which were 

 collected by my son, S. V. Duncan, who has assisted me in this 

 research, and one has the so-called teeth and jaws. There is a most 

 instructive series of casts in flint of the species in the British 

 Museum. Altogether I have examined about one hundred fairly 



1 Vol. xxvii. '■^ Vol. i. part 6, on the Eohinoconidce. 



3 p. 221 et seq. plates xlix. figs. 2, 3, 4. Plate 1. fig. 1-6. * p. 213 et seq. 



