466 TEMNECHINUS MACULATUS. 



TEMNECHINUS. 



Temnechinus Forbes, 1852, Monog. Brit. Tertiaries. 

 (See Part II. p. 285.) 



Temnechinus maculatus 



IGonocidaris maculata A. Agass., I860, Bull. M. C. Z., I. 

 ! Temnechinus maculatus A. Agass., 1872, Rev. Ech., Pt. I. p. 165. 

 (Sec Part H. p. 286.) 



PL VIII. f. 1-18. 



Straits of Florida ; Azores. 



MICROCYPHUS. 



! Microcyphus Agass., 1841, Vai.., Anat. Genre Ech. (non Mon. Scut.). 



The tubercles in this genus are small, not numerous, limited to a portion 

 of the coronal plates, leaving in the interambulacra marginal hare spaces; 

 in the ambulacra the tubercles are regularly arranged. The poriferous 

 zones are narrow ; pores arranged as in Salmacis, in double irregular ver- 

 tical rows. The secondary tubercles, according to age, encroach more and 

 more upon the coronal plates, leaving thus bare spaces remarkably different 

 in specimens of different sizes ; the actinal opening is angular, not indented ; 

 the abactinal system is compact ; the test is stout, The spines are thin, 

 slender, short, resembling those of Mespilia ; the sutural pores are indistinct 

 in the median interamhulacral and ambulacra] spaces, though frequently well 

 defined at the junction of the poriferous zone and the interamhulacral plates. 



Microcyphus maculatus , 



! Microcyphus maculatus Agass., 1841, Val., Anat. Genre Ech. 



PL VIII". f. 8-io. 



In specimens measuring 37 n,m in diameter the test is stout, depressed from 

 above ; outline pentagonal, slightly re-entering towards the median interam- 

 hulacral line. In the interamhulacral space the tubercles above the ambitus 

 are of uniform size, slightly smaller towards the median line, covering closely 

 with the crowded miliaries placed between them, the central part of the 

 coronal plates, and so arranged as to leave a bare lozenge-shaped area parallel 

 with the horizontal sutures of the plates. These bare sjjaces rapidly decrease 

 towards the ambitus and disappear completely on the actinal surface, where 

 the tubercles are larger, occupying the whole of the coronal plates. The pits 

 at the angles of the plates are well-marked on the actinal surface along the 

 median as well as the horizontal sutural lines. In the ainbulacral space the 



