1880.] 



PROF. F. J. BELL ON THE TE.HNOPLEURID^. 



431 



their tips ; the upper ones are banded with brown, those near the 

 ambitus with purpHsh brown ; those around the actinostome are 

 flattened, and the bands become distinctly purple, while the green 

 is evanescent. 



The denuded test, though not unlike that of S. bicolor, is distin- 

 guished from it by its depressed actinostome, the greater height of 

 the ridges connecting the auricles, the somewhat narrower ambulacral 

 pore-areas, and the more distinct sutural pores. The changes 

 during growth in the proportional size of the actinostome are some- 

 what striking; and I regret that it is only in the lately acquired 

 specimens that the abactinal and anal areas are complete, so that it is 

 impossible to trace the changes which occur in this region. Prof. 

 Agassiz's specimens seem to be in a somewhat similar plight ; for he 

 is only able to give the measurements of the abacthial and anal 

 systems of one of his specimens ; the percentage value of the 

 abactinal area in the specimen measured by him is 18-5. The great 

 changes in the proportions of the actinostome point to the necessity 

 of carefully examining a series of forms before using the size of this 

 orifice as a specific character. 



It may be of interest to point out that there is in the Museum col- 

 lection a specimen which, resembling very closely the S. conica of 

 von Martens, appears to bear out the view of Prof. Alex. Agassiz 

 that S. conica is synonymous with S. sulcata. Von Martens's spe- 

 cimen measured 72 millims. in diameter and 55 millims. in height, 

 thus giving the latter a percentage value of 76'3 ; the specimen now 

 under description had a diameter of 77 millims., and the percentage 

 yalne of the height, abactinal and actinal areas, were respectively 

 65, 15-5, and 22. 



Some link is yet wanting to connect with these conical specimens 

 of S. sulcata a specimen from an unknown locality, the height of 

 which is 91 per cent, of the diameter, and which hardly conforms, 

 iii some other points, to the ordinary specimens of this species. 



. 5. Salmacis globator. 



Two distinct species appear to have been described under this 

 head— one by Agassiz & Desor, in the Catal. Raisonne (Ann. Sc. 

 Nat. (3) vi. p. 359), the other by Prof. Alex. Agassiz, in the 

 * Revision of the Echini' (iii. p. 475). Oue point will suffice to 



