BIIIANG TILL K. SV. VET.-AKAD. IIANDL. BAND 13. AID. IV. N:0 5. 177 



16. ECHINUS PLACENTA L. 



EcHiNus planus, orbieulatiis, ambulacris quiiiis bipar- 

 titis, ano marginali. 



Prjeleclioiies 17.52. 



Guultieri, f. 110, f. G. 



S. N. ed. 10, 1758, M. L. 1., 1704, et S. N. ed. 12, add. 



Rmnph. mus. t. 14, f. G. 



Fet. amh. t. 11, f. 5. 



Breyn, echin. 64. t. 7, /". 7, 8. 



Klein, echin. t. 20, f. A. B. (ed. gerin.) 



S. N. ed. 10 et 12. 

 Hahitat in Occano nieridionali. 



Testa orbiculata, plana, inermis, margine quinquies 

 obsolete emarginato, a^qiiali: uiiica emarginatura 

 profuiidiore ; ante bauc foramen in pagina superiore. 

 Supra striata. 



Foramen centrale obtuse qiiinquangiilare. 

 Radii 5 alterni, lineai^es, excavati. 

 Suhtus striata piinctis minimis, eminentibus, circulo 

 inscriptis. 

 Foramen centrale obtuse quinqiiangulare, cinctum 



area rotimdo-pentagona. 

 Eadii o lineares, superioribus oppositi. 

 5 latiores obsoleti. 



The Lectiire of 1752 lias: »is called Placenta from its being 

 Hat as a pancake». 



Fn thc collectiou tliere are two well-preserved specimcns 

 willi printed labels attached: Echinns placenta. ^^Foramcu 

 centrale» refers to the soniewliat dcpressed »centrum». The 

 »Radii lineares excavati? are thc impresscd median sutures 



12 



