(»G SVEN LOVEN, ECHINOLOGICA. 



radiating perfnrations. Owing to tlie reoumbent position of 

 tlie dental slide, the triangulär area, tr.^ eomes to rest npon 

 the racliis, and the inner wing almost to coineide witli the 

 iipper area. The triangle, tr., is long, narrow and smooth, 

 and when the intermuscnlar slieet is removed, //V/. 84, it is seen 

 to be solid altogether. The lameilar partitions, fig. 83, 84, 

 of the inner wing are nearly as regular as those of the outer 

 wing, partly dendritic ; they are joined to the adoral börder of 

 the triangulär body by a few short branches only, that leave 

 between theni large lacnnes, opened when the inter-muscular 

 sheet is taken away. The inner wing thus has become verv 

 large in proportion, fig. 80, 81, 84. The minuts auricles, see 

 woodcut, p. 78, arise from the interradiura, whieh is broad, and 

 are uuited into one single piece for each tooth, flattened eon- 

 centrically, rather narrow at the base, then expanded, bilol)ate, 

 and contracted, truncated at the top. Along the margin, on 

 either side, are attached the thin, horizontally directed retrac- 

 tors, fig. 80, m. re., whieh are inserted, on the interiör side of 

 the pyramid, in a prominent horse-shoe-shaped, walled impres- 

 sion, fig. 82. The very slender protractors, fig. 80, m. pro., whieh 

 are attaehed, close together, near the top margin of the auricle, 

 are inserted on the tuberosities near the external margin of the 

 pyramid. The teeth. Fl. VIII, fig. 80, 83, Fl. XI, fig. 148, 

 are long, higli, curved inward, the 5 largest, then the 1 and 

 4, the 2 and 3 smaller, the crown somewhat concave, the back 

 prominent adorally. 



The Echinarachnius Parma Lamck., Fl. IX, fig. 86 — 93, 

 Fl. X, fig. 135, 130, 137, 138, Fl. XI, fig. 142, 147, 151, has 

 the dental system rather high, stellate, with tlie rays short 

 and broad, the ray 2h 3 a, answering to the ambulaerum ///, 

 slightly longer. The sides are symmetrically slightly unequal, 

 the 5 being to 1 and 4 = 1 : 0,7 6, to 2 and 3=1: 0,9.5. The 

 alveolar arabitus is as that of the Enrope emarginata Leske, 

 the supra-alveolar erests exceeding the margins of the reenter- 

 ing angles. The dental slide is feebly eonvex. reoumbent at 

 an angle of about 15°. The area of the symphysis, less 

 pointed above, is less expanded below, fig. 89, not far from li- 

 near. The pyramid, in its dorsal aspect, fig. 87, is like that 

 of Encope with the deep lacune between the crest and the 

 inner wing larger, fig. 87, 89, 90, the mesial tuber in the 

 external angle entire, the supra-alveolar proeess strong. The 



