Mr. C. 0. Waterhouse on new Goleoptera. 377 



radially arranged mesenterial sacs, tentacles with urticating 

 capsules, and indifferent aquiferous pores. Although in 

 certain Sponges at an early period radial diverticula surround 

 a central cavity, there are also Sponges, such as the Ascones, 

 which never develop such diverticula, and others (the Sycones) 

 in which they only originate as sacculations of the wall. But 

 that the Ascones are not retrograde forms may be inferred 

 from the circumstance that the Sycones, long before they 

 form radial tubes, present the pure Ascon type. It is there- 

 fore very probable that the oldest Sponges possessed no radial 

 diverticula of their central cavity, but, like Olynthus among 

 the Calcispongige, had a simple sac-like form. 



XXXIII. — New Goleoptera recently added to the British 

 Museum. By Charles O. Waterhouse. 



Scarabaeidae. 



Scaraboius Thomsoni, Bates, in litt. 



Supra cupreus, subtus olivaceus nitidus ; tibiis nigris. 

 Long. 16 lin. 



Somewhat bright uniform copper-colour above, very dark 

 olive-green below. Thorax very convex, obliquely nar 

 rowed in front and posteriorly ; densely asperate at the sides ; 

 the disk strongly punctured, the punctures moderately 

 large, each with a minute puncture in the middle ; the 

 punctures on the posterior part of the disk are irregularly 

 placed, but are generally separated from each other by about 

 the diameter of a single puncture ; the surface between the 

 punctures shining, with a few minute punctures here and 

 there. There is an irregular smooth median line. The 

 sides are very regularly crenulate, somewhat angular at 

 the middle, very gently sinuate behind the middle. Elytra 

 distinctly narrower than the thorax, moderately convex, con- 

 siderably sloping down behind the middle ; the suture 

 shining, with a few small punctures ; the rest of the surface 

 dull, especially towards the sides, densely and finely rugu- 

 lose ; the rugas having a tendency to run longitudinally 

 produces an appearance of the surface being scratched ; the 

 first interstice has a few shallow punctures ; the second, third, 

 fourth, and fifth interstices have more numerous, moderately 



