356 PEOF. p. M. DUWCAS^ ON THE MOEPHOLOGT 



Desor states, in his ' Synopsis des ^chinides,' p. 105, with 

 reference to Temnopleurus: — " C'est par erreur aussi que M. Porbes 

 pretend qu'il existe des pores aux angles des plaques coronales 

 comme dans les Salmacis." Now typical Temnopleuri certainly 

 have pits at the angles o£ the plates, and something more than 

 deep sutural impressions there. Hence the Nummulitic forms 

 are not true members of the genus Temnopleurus. The numerous 

 members of the subfamily Temnopleuridae which Mr. Sladen and 

 myself are now describing from the lowest Nummulitic rocks 

 have very decided rib-like ornamentation, and, of course, what 

 are called grooves ; but they are not pitted. So that all these 

 Eocene forms from Sind must come under one or more genera 

 with a raised rib-like ornamentation, without pits. They re- 

 semble in many points Trigonocidaris, Agass., and JParadoxecMmis, 

 Laube. 



"With regard to forms having pits, Temnopleurus is typical. The 

 generic differentiation of Salmacis sulcata and a typical species of 

 Temnopleurus is insufficient. Amhlypneustes is approached through 

 Salmacis hicolor. I do not think it possible to admit TemnecMmos 

 maculatus, A. Agass., amongst the Temnopleuridae with pits until 

 Agassiz has examined the sutures. 



If the subfamily is to be rearranged according to these 

 views, the oldest forms will form the group with depressions 

 on the test in the line of the sutures, or, rather, with raised 

 ribs. 



The second group will consist of the genera Temnojpleurus, 

 Salmacis, and Amhlypneustes and others with true pits. 



It is interesting to note that the earlier forms of the Temno- 

 pleuridae resemble the immature individuals of recent species, and 

 that the immature individuals of ^e«2«o/)Zez^rws toreumaticus might 

 be asspciated with some species of Salmacis. 



DESCEIPTION OP PLATE YIII. 



Fig. 1. Salmacis sulcata. Superficial view of the pits on the interradial median 

 line. The sutural markings are distinct ; and each pit transgresses on 

 the substance of the angle of a plate especially. Magnified. 



Fig. 2. An older specimen. The sutural marginal lines are more distinct. The 

 pits are about the same size as in fig. 1 ; but there are depressions 

 or semi-pits ou the vertical sutures between the others a and b 



