12 Prof. P. Martin Duncan— On Galerites alhogalerus, Lamk. 



thick." "The anus is inferior and sub-marginal." "The mouth 

 appears round, but is obscurely decagonal, being gently notched at 

 its margins opposite the avenues of pores. It is inflexed opposite 

 each area, the inflections opposite the interambulacral areas being 

 deeper and semicircular. The pairs of pores are small, ranged in 

 single file down the dorsal surface, falling into series of three pairs 

 on the base soon after passing the margin. The series become more 

 and more oblique until, at a tenth or eleventh from the base, they 

 are directly under each other, and consequently give considerable 

 breadth to the avenues. Three lines drawn up each avenue in the 

 inner half of its basal course will intersect one of the pairs of pores 

 of each series." 



" The apex of the body is the highest point of the back. The 

 apical disk is formed of five genital and five ocular plates. Four 

 of the former are perforated, for the oviducts, in their lower halves ; 

 one of the perforated plates is greatly enlarged above, to form the 

 centre of the disk, where it is wrinkled and punctured, constituting 

 the madreporiform plate. The fifth posterior odd genital plate is 

 very small, triangular, and imperfoi'ate." 



" The existence of a dental system in Galerites was made known 

 by Mr. Charles Stokes." "A second specimen with teeth adorns 

 the collection of Mr. Bowerbank, and in it the dental lantern is 

 sufficiently protected to enable us to determine the form and 

 structure of its principal elements. The teeth are smooth, white, 

 lanceolate, triangular, each consisting of a concave lamina, terminat- 

 ing below in the dental point, and straightened on its back h^ 

 a prominent rounded ridge." In the plate drawn by Bone after 

 Forbes, the whole of the type, seen from the side, clearly indicates 

 that the base is not flat (Fig. 1) : the anus is distinctly inferior and 

 submarginal (in Fig. 2) : the ambulacral plates are rectangular and 

 equal, the pores are oblique (Fig. 5) : the triplets are well shown 

 (on Fig. 6). The teeth are shown, three placed side by side and 

 quite close ! ! ! (Fig. 10, and magnified in Fig. 10a). A single tooth 

 magnified is shown at h. Figure 12 shows the posterior ocular 

 plates widely separated by the fifth genital plate, and the anterior 

 edge of the left posterior ocular is in contact with the madreporic 

 plate. 



Cotteau et Triger in their Echinides du Departement de la Sarthe, 

 1859, classify the sjDecies now tinder consideration with the genus 

 EcUnoconus of Breynius, 1732, and give a long list of synomyms. 



Omitting all considerations regarding the generic title, these 

 authors may be said to have given much more correct morphology 

 than their predecessors. 



Their Echinoconus conicus^= Galerites alhogalerus, ^ar. pyramidalis, 

 var. angulosa. They state that the base is perfectly flat, the inter- 

 ambulacra furnished with little tubercles crenulated and perforated 

 without serial order, distant abactinally, closer, larger, and more 

 scrobiculate at the ambulus and actinally. Intermediate granules 

 abundant, unequal, and sometinus irregular. Ambulacra narrow, 

 provided w th tubercles similar to those in the interradia; however, 



