On the Spongia coriacea of Montagu. 17 



quantity during the male sexual maturity, and diminish sub- 

 sequently in amount, not only relatively but absolutely. 

 Nevertheless, I only wish to indicate a possibility ; it seems 

 a more probable supposition that these urinary concretions 

 originate in the blood and are deposited in the wall-less blood- 

 lacunre, the most important of which indeed run along the 

 intestine. The decrease of these pigment-secretions coincides 

 with the commencement of the sedentary mode of life, and 

 therefore also with the complete change of nourishment, and 

 may consequently be caused thereby instead of by the disap- 

 pearance of the fatty body. 



That the rectal vesicle produces a strongly smelling sub- 

 stance, as Fraisse asserts, may be correct ; but I cannot contirra 

 it, as unfortunately (or shall I, as a zoologist, say fortunately ?) 

 I possess a very feeble sense of smell. 



The other internal organs of the Cryptoniscidte show no 

 great differences from those of the Bopyrid^ ; what there is 

 to be said about them and about the details of the external 

 organization I reserve for my monographic publication. 



II. — On the Spongia coriacea of ilfow^a(7M, = Leucosolenia 

 coriacea, Bh.^ together with a neio Variety of Leucosolenia 

 lacunosa, Bk., elucidating the Sjncular Structure of some 

 of the Fossil Calcispongiw ; followed hy Illustrations of the 

 Pi7i-like Sjncidcs on Verticillites helvetica^ De Loriol. By 

 H. J. Carter, F.R.S. &c. 



[Plate I.] 



In 1871 (' Annals,' vol. vii. p. 278) I gave a nomenclatural 

 account of Montagu's Spongia coriacea =Grantia clathrus, 

 Sdt.,= Leucosolenia coriacea^ Bk.,= Clathrina clathrus^ Grray, 

 under the last name, which was subsequently changed by 

 Hiickel into Ascetta clathrus (' Die Kalkschwamme,' vol. ii. 

 p. 30), and now I propose to add the result of a structural 

 examination, chiefly on living specimens, of this calcisponge 

 from this place, viz. Budleigh-Salterton, South Devon. 



In limine, however, it is necessary to clear up the confusion 

 that has arisen from Hackel having made a separate species 

 of vSchmidt's Grantia clathrus under the name of Ascetta cla- 

 thrus, with a different form of spicule from that which Schmidt 

 has given as characteristic of it (Spong. Adriatisch. Meeres, 

 Suppl. p. 24, Taf. iii. fig. 3 a), and which accords with that 



An7i. (& Mag. N. Hist. Ser. 5. Vol. xiv. 2 



