26 Mr. II. J. Carter on the 



of Le Mans, that Calcisponges existed in a fossilized state, I 

 was inclined to discredit the fact, as my actual experience of 

 the delicate structure and perishable i^ture of the spicules of 

 the Calcispongiai then seemed to point out that their structure 

 and spiculation was such that thej must inevitably go to 

 pieces immediately after death, and therefore that the proba- 

 bility of a Calcisponge becoming fossilized was very doubtful. 



When, however, convinced of the error I fully expected 

 that recent specimens would be discovered which would ex- 

 plain all the then anomalous structure and spiculations in the 

 fossil ones ; and the first that tended chiefly towards this was 

 the discovery, by Dr. Hinde, that the fibre of his Verticilliles 

 d'Orhignyi from the Upper Greensand of Warminster Avas 

 composed of three- and four-rayed calcisponge-spicules, which 

 were so far loosened by disintegration that they could be 

 easily extricated entire, and thus viewed under the microscope, 

 mounted in balsam or otherwise, indeed a simple lens is 

 sufficient (^Annals,' 1882, vol. x. p. 192 et seq. pi. xi.). 

 At the same time Dr. Hinde discovered in his Sestrostomella 

 rngosa from the Cretaceous of Vaches Noires, near Havre 

 (ibid. pi. X. fig. 4, and pi. xii. fig. 12, &c.), the two-pronged 

 " tuning-fork "-sha])cd minute spicule first represented by Dr. 

 Bowerbank (Mon. Brit. Spong. vol. i. p. 268, pi. x. tig. 2o7) 

 from a recent calcisponge at Freemantle, in S.W. Australia, 

 and subsequently by Hiickel in his Leucetta pandora from 

 the Gulf of St. Vincent &c. in S. Australia (' Die Kalk- 

 schwamme,' Atlas, Taf. xxiii. fig. A). I was myself able 

 also to confirm these observations respectively in Verticillites 

 anasiomans from the Coral Bag of Faringdon and in a speci- 

 men of Sestrostomella irova the Jura, kindly sent me by Zittel, 

 when I also published the illustrated description of the little 

 calcareous sponge from Freemantle, in which the clathrous 

 structure was shown to be formed by the reticulated union of 

 a thread-like element similar to that of Clathrina coriacea and 

 Lencosolenia lacunosa^ but, as before stated, solid like the stem 

 of the latter, and not holloic like the tubular thread of the head, 

 being composed of a layer of small triradiates externally with 

 a much larger and different triradiate-form axially or within 

 (' Annals,' 1883, vol. xi. p. 33, pi. i. figs. 13-15) ; and now I 

 have had the opportunity of describing one from the coast of 

 England, in which the " filiform spicules," together with the 

 solid fibre in the fossil species, also receive an explanation from 

 a recent species. 



The specimens of this sponge, which are in spirit, were 

 gathered on the pier at liamsgate by Mr. Hillier, after whom 

 1 have designated the variety, and presented to me by Mr. 



