AFFINITIES OF THE GENUS SIPH.ONIA. 801 



three families Eudeens, Siphonocoeliens, and Jere'ens, the first two of 

 which receive most of the genera of D'Orbigny's Siphonidae, and are 

 distinguished from the latter by the isolation of their tubules, which 

 in the Jereens are grouped together in fasciae or in series. This dif- 

 ference the author is able to maintain in the case of Siplionia, appa- 

 rently by never having examined actual specimens of the genus ; at 

 all events among his rechauffees figures of Sowerby's S. pyriformis, 

 taken at second hand from D'Orbigny, there is one illustrating a sec- 

 tion said to have been made longitudinally through the sponge, which 

 does not exhibit the longitudinal tubules which are the most well- 

 marked canals of all in Sowerby's faultless drawings, and in all 

 specimens which have come under my own observation. Any thing 

 more misleading than the section, fig. 12 a, pi. i., can scarcely be 

 imagined. 



Siplionia is distinguished from the other genera of this family by 

 being borne on a stalk, and is divided into two distinct new genera, 

 Siphoneudea and Poly siphoneudea, the latter founded on Siplionia 

 arbuscula, Mich., and distinguished from the former by bearing 

 several sponge-bodies on its raceme instead of a single one. The 

 distinction is a trivial one, and scarcely of specific importance even. 



The mistake made by earlier authors of regarding the specialized 

 pore-areas on the exterior surface of the sponge as representing 

 oscular openings is repeated here, and, I believe, by every one who 

 has had occasion to mention them both before and since. 



1861. Courtiliier, A. "Eponges fossilcs des sables du terrain Cre'- 

 tace superieur des environs de Saumur, etage Senonien de 

 D'Orbigny" (Extrait des Annales de la Societe Linneenne de 

 Maine-et-Loire). 



This author simply describes a number of species of Siplionia, the 

 names of which will be found in the appendix. His specific dis- 

 tinctions are founded on slight variations of external form, so slight 

 sometimes as to lead one to wonder whether he has not given a 

 separate name to each individual specimen in his collection. 



1884-66. Eomer, F. A. " Die Spongitarien des norddeutschen 

 Kreidegebirges," Paleeontographica, vol. xiii. pp. 1-64. 



Komcr follows D'Orbigny and Fromentel in his classification, 

 adopting, as Pomel remarks, the errors of both, which he modifies 

 according to Etallon, or from his own inspiration, or Toulmin Smith. 



The Siphonidae are stated to possess " wurmformig " (Lithisticl) 

 structure externally, sometimes combined with a " gitterformig " 

 (Hexactinellid) structure in the interior. This is as mythical a 

 combination as the organism of the legendary " Griffin," and can 

 only be explained on the supposition that a Lithistid sponge has 

 grown over a Hexactinellid to the extent of enclosing it. In the 

 forms I have examined certainly nothing of the kind is to be seen. 



The genus Siplionia is defined according to Fromentel, whose 

 genus Poly siplionia is accepted without comment ; while the Aslylo- 



