C^S SVEN LOVEN, ECHINOLOaiCA. 



Ill the Laganiim decagonale Blv., Pl. IX, flg. 94 — 101, TI. 

 X, fig. 1S9, Fl XI, ftg. 143, 152, the dental system is liigli, peii- 

 tagonal, tlie rays very sliort, tlie sides beiiig only feebly reeii- 

 teriiig-, symmetrically uiiequal, the 5 beiiig to the 1 and 4 as 

 1:0,74, to the 2 and .') as 1 :0,7i. The amhitns formed by 

 the five strong alveolar crests, fig. 143, is conformable, pen- 

 tagonal, the wings 1 a .7 h and 5 a 4 1 1 bnt slightly extended 

 on the rays I and V. 



The dental slide, fig. 94, 98, is a very little concave, al- 

 most straight, recnmbent at an angle of about 37 \ The area 

 of the syniphysis, fig. 98, is broadly lunate. the external out- 

 line being regnlarly arcuated. The pyramid seen from above, 

 fig. 95, is, like that of the preceding, arrow-headed, its erest 

 is very strong, transverse, witli the tuberosities doubled. Tlie 

 lamell ated inner wiiig is raised and adjoins the crest with a 

 depression bnt without any interjacent lacuiie. The epiphysis 

 is liigh, a simple lamella, fig. 94, 95, 100. There is no ro- 

 tnia. The nnder snrface, fig 96, 97, nnconformable, is not 

 level, bnt strongly bnlging, the middle compact part convex, 

 externally inflected, the tnber simple, the mesial ridge di- 

 stinct; the lamellated borders rising, mnch expanded, ronnded, 

 a large laeune separating tliem from the crest. The pyramid 

 5, fig. 97, 143, is large and eqnilateral, the 1 and 4, fig. 96, 

 143, smaller, ineqnilateral, the a side of the 1, and the h side 

 of the 4, both oontignons to the 5,' expanded and ronnded; the 

 2 and 3 have their contignons sides larger. The labial process 

 is inflected, broad. The lateral sheets, fig. 94, 98, 99, are 

 broadly obovate, slightly emarginated for the epiphysis, the 

 curves of accretion distinct, the radiating ridges slight and 

 few, withont perforations. The rachis, which is not marked 

 with holes. coincides with the onter limit line of the triangu- 

 lär area, fr., which is compact and divides the whole into a 

 larger lower area and a smaller upper, fig. 94, 99. When the 

 intermuscular sheet is removed, fig. 99, the radiating ramified 

 lamellate partitions are seen to issue from either side of the 

 fr. The inner wing, about lialf as large as the outer, has its 

 radiating lamels regular. not intercepted by any lacunes. The 

 auricles, fig. 101, like tliose of Eucope, arise from the interradium; 

 tliey are united into one single piece for each tooth, flattened con- 

 centrically, thin, narrow below, then expanded, slightly lobated. 

 Aloiig their margins the two strong bipartite retractors are 



