115 



Divis. 2. With rows of lines proceeding from the vertex, but not 



reaching to the margin.* 

 Part II. Echini, in which the shell has only one opening, and that 



placed in the centre of the base. 

 Sect. I. Echini, set with very small tubercles, with ten rows of 



short lines not reaching to the margin, but so disposed 



as to form a figure on the surface resembling the leaf of 



cinquefoil, and therefore not improperly sailed penta- 



phylloides 

 II. Echini, with larger and more prominent tubercles, and 



with rows of lines or tubercles reaching from the vertex 



to the mouth, called ovarii.^ 



The indefatigable Klein, in his Naturalis Dispositio 

 Echinodermatum, published in 1734-, not only improved the 

 classification, but added considerably to our knowledge of 

 these substances : from the situation of the mouth, he dis- 

 tinguished them into emmesostomi, when the mouth was 

 placed in the centre of the base ; and apomesostomi when 

 out of the centre. When the vent was in the upper part, he 

 designated them anocysti ; in the under part, catocysti ; and 

 in the side, pleurocysti. Considering these as classes, he 

 formed the following arrangement, by placing under each of 

 the three last as many of these substances as respectively 

 accorded with the class, but which differed from each other 

 in some respects as to their general form, and the situation 

 of the mouth : these he subdivided, according to other less, 

 but constant distinctions, into genera. 



* These he instances in a specimen of scutum or echinanthus. 



f It will be observed in this arrangement of Woodward, that 

 he separates these substances into two divisions ; spatagi, having 

 two openings, and echini, having only one opening, at the base of 

 the shell. 



