Pyritized Sponges. 4 1 7 



exaiuiile <it' the alxjve species figured by G. 8owerby,i under the 

 name of SipJio/ila pyrifi)rinis (non Cxoldfuss), and I'e-figured by 

 Zittel.2 



Specimen B. (Phite LXXXII., Figs. 2 a, h.) 



In form this fossil is subcylindrical, slightly rcLairved, that is 

 to say, concave and convex on opposite lateral faces resjDectively ; 

 bluntly rounded at the apex, with a conspicuous cloacal aper- 

 ture, now filled with a projecting plug of pyrites, from which 

 radiate a few irregular and obscure (?) excurrent canals. Distal 

 end furnished with a short stout stalk, which, at the junction 

 with the sponge body, is seated in a. slight depression. Surface 

 of sponge relieved Avith lobular swellings. In places the sui'face 

 shows patches of especially verrucose character, which may be 

 the vestiges of former areas of the incurrent system of canals. 

 This structure is now, however, obscured by the development of 

 crystal facets over the surface of those areas. 



Measurements. — Greatest length of body, 45 mm. 



Greatest diameter of body, 32 mm. 



Diameter of cloacal opening, 5.75 mm. 



Length of peduncle, 11 mm. 



Width of peduncle, 7.25 mm. 



Remarha on specimen 5.— This example at first sight ap- 

 peared to belong to the genus PJiymateUa, Zittel, on account of 

 its subcylindrical form. The rounded summit and shape of the 

 cloacal area, however, and the impressed pediuicular seat ex- 

 clude it from that genus. On the other hand, certain sub- 

 cylindrical varieties of Siphonia tulipa, Zittel, show that our 

 specimen is related to that specific type: Thus, a closely com- 

 parable form is that figured b*' Sollas,'^ under the name of S. 

 pyriforniis. Sow., var. cylindrica, Coui'tillier. We here follow 

 Dr. G. J. Hiude^ in placing Sowerby's species pyriformis, and 

 also Prof. Sollas' so-referred species shown in his Figures 1, 3, 

 4, 6, 8 {loc. cit.) with Zittel's ,S'. tulipa. We may therefore re- 

 gard this Queensland fossil as probably referable to (S'. tulipa, 



1 Geol. Trans., Series 2, vol. iv., 1836, p. 34C, pi. xva., figs. 4 and 5. 



2 Traite de Palcotitologie (French ed.), 1883, vol. i., Paleozoologie, ]). 169, fig. 80i. 



3 Quart. .Jour. Geol. Soc, vol. xxxiii., 1877, pi. xxv., fig. 4. 



4 Cat. Foss. Sponges, Brit. Mus. (Nat. Hist.), 1883, p. 64. 



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