58 SVEN LOVEN, ON THK FXIIINOIDEA IJESCRIBED BY LlXNy1-:US. 



is dividcd into radios, like a står . In the tirst edition of the 

 Svstema Natur?e, 1735, tliey are placed in that same Order, 

 tlierc called Zoopliyta, wbile »Vermes> lias beeome the uame 

 of tlic Class; in tlie seeond edition, 1740, tliey have been se- 

 parated and Eebiniis removed to tbe Testacea, but in the 

 sixth, 1748, they are again brougbt together under Zoophyta. 

 Li>«N.EU.s now in the Lectures declares that the Ecbini differ 

 from the Startishes merely gradn», strong}}- insists iipon the 

 diversity betAveen their »testa» and the »concha» and »cochlea» 

 of the Testacea, and, correcting a statement in tlie sixth 

 edition, points out as of particular importanee the mobilitv 

 of their spines. 



: Specimens», he says, sare most highly valued in which 

 all the spines are preserved. But in this condition the clia- 

 racters of the species are not to be distinguished. and it has 

 therefore beeome a general practice to remove the spines by 

 cooking;). At that time all the specimens in the Qucen's 

 Museum, perhaps with a singie exception, the Eehinus escii- 

 lentus, Avere thus deuuded. and it was for the solid frame- 

 work then coming into view that LinN/EUS created his termi- 

 nology. Unacquainted, it seems, with Eéaumur^s observations 

 of 1712, he bad, exeept with regard to the mouth with it>s 

 teeth and the excretory opening, no distinct idea of the external 

 organs and their functions, and thus preferred to adopt for 

 them insianilicaut terms havino- no reference at all to their 

 use in the cconomy of the animal. ;The exteriör of an Eehi- 

 nus», he said, vmay be likened to a garden Avith its beds and 

 walks. Tlie arefe, eonvex and broad, are like the beds, the 

 ambulacra are like the walks between them, impressed and 

 narrow, and these are ahva}s perforated verv minutely, like 

 a lady"s laee». 



The special terminology of the descriptions is as follows. 



The general form of the Testa is stated, from E. Cidaris 

 to E. Placenta, as: globosa, hemisphnprica, qualiiied by the 

 addition of gibba-) or depressa^), which refers to the dorsal 

 centrum; planiuscula, plana. In the Echinometne, the Spatangi, 



') S. N. eil. 10, p. 66;{, note. 



') »Folium gibbum, (luod utramque superficieru facit convexam. Phil. 

 bot. p. 46, 75. 



') Folium depressum, quocl in disco magis deprimitur quam ad latera. 

 ]'hil. bot. ib.. 77. 



