186/.] MR. G. R. CROTCH ON AZOREAN COLEOPTERA. 359 



which differs in its construction from all the other specimens of that 

 genus known to us either in the French Museum or in the English 

 collections. This sponge is about 8 inches in height, 2| inches in 

 diameter at the apex, and 1 1 inch at the base, and the body is cy- 

 lindrical. The parietes of the sponge are of about the same thick- 

 ness as those of A. speciosum. The primary lines of the skeleton 

 are wide apart, irregular, and run diagonally and flexuously over its 

 surface. The basal end of the sponge is closed and rounded, and 

 one side of it is rather longer than the other, and there is not the 

 slightest indication of its having been furnished with prehensile spi- 

 cula similar to those of ^. speciosum. The attachment of the sponge 

 is partly on one side, in the form of a thick incrustation, and partly 

 close to the base, by a similar patch of thickened tissue. 



But the most striking and characteristic diflFerence in its structure 

 is in the apical termination of the sponge, which is totally destitute 

 of the great marginal ring that surrounds the oscular area in A. spe- 

 ciosum, the sides and oscular area merging in each other insen- 

 sibly and without the slightest trace of a boundary line. In this 

 character this species closely resembles the distal extremity of PoJij- 

 mastia manimillaris and other species of that genus, which have not 

 the oscular area confined within a marginal ring. . 



The specimen appears to have been too well washed, as no remains 

 of interstitial spicula could be discovered with a 2-inch lens. The 

 sponge is exceedingly beautiful, and the skeleton-structures appear 

 by the aid of the lens like twisted spun glass. 



Beside those described above, there is another specimen of Alcy- 

 onceUum in the Museum of the Jardin des Plantes, which is also 

 named A. corbicula ; but it differs so much in its structural cha- 

 racters as to render it highly probable that it is a distinct species. 

 It is about 5 inches in height, 2h or 3 inches across at its apex, and 

 at the base it is Ig inch in diameter. The base is round and smooth, 

 but the body of the sponge assumes a square form. The texture of 

 the sponge is very much thickened and woolly in appearance, and 

 the spaces in its sides much larger than those in the other specimen 

 designated by the same name. The primary lines of the skeleton 

 are ratlier flexuous towards the base of the sponge, but they become 

 more regular and straight as they approach its apex. There are no 

 indications of elevated ribs either on the exterior or interior of this 

 sponge. I have bad no o})portuiiity of examining its strtictural pe- 

 culiarities ; but I have little doubt of their being different from those 

 of the sponge bearing the same name in the French collection. 



8. On the Coleoptera of the Azores. 

 By George 11. CrotcHj jM.A. 



(Plate XXIII.) 



The Azores, though not less interesting, have yet received a far 

 less share of attention, as far as their fauna is concerned, than the 



