On CarbonrferoHS Sjjonges from Ayrshire. 425 



the base of each antenna ; cheeks green. Thorax rather 

 narrower than the width of the head across the eyes, convex, 

 narrowed at the base, the anterior and posterior borders 

 metallic, sprinkled with roundish tubercles; the disk gibbous. 

 There is an obtuse tooth at the side just before each posterior 

 angle ; the base is gently arcuate, not lobed in the middle. 

 Elytra narrowed at their base, dull black, slightly tinged with 

 blue, the surface densely covered with conical tubercles which 

 are directed backwards ; each elytron has a small rusty spot 

 near the base and another near the apex. The elytra are 

 connate. 



Hab. S.E. Africa, Lake Nyassa. Brit. Mus. 



A female example in Mr. Janson's collection has the elytra 

 more ample, immaculate, and the sutural angle blunted. 



LV. — On a Carboniferous Hyalonema and other Spom/es from 

 Ayrshire. By Professor J. YoUNG and Mr. J. YoUNG, 

 F.G.S. 



[Plates XIV. & XV.] 



The rotten limestones of Cunningham Baidland, near Dairy, 

 in Ayrshire, were well known to Glasgow geologists, but, 

 singularly enough, the value of their contents was unknown till 

 the spring of 1876, when Mr. John Smith, of the Eglinton 

 Ironworks, Kilwinning, Avashed the powdery debris and ob- 

 tained, besides brachiopods, corals, &c., a quantity of sponge- 

 spicules, which he submitted to us for identitication. We 

 exhibited Mr. Smith's collection to the British Association at 

 its Glasgow Meeting in Sept. 1876, and in autumn to the 

 Natural History Society. As no siliceous sponges had pre- 

 viously been found in our Carboniferous strata, we referred the 

 spicules provisionally to McCoy's Silurian genus Acaritha- 

 spongia. In the same strata Serimla parMela^ M'Coy, is 

 abundant ; and as a continental paleeontologist, whose name 

 we have unfortunately lost, had already identified this fossil 

 as a glass sponge allied to Hyalonema, we suggested that the 

 spicules and the glass rods might possibly be found to belong- 

 to the same organism. 



In the ' Catalogue of Western Scottish Fossils,' prepared for 

 the British Association Meeting of 1876, one of us briefly 

 referred to the spicules and our conjecture of their being a 

 part of a Hyalonema ; but, in defect of direct evidence, the 

 fossils were catalogued " Acantlmspongia Smithii, Y. and Y.,= 



