PERONELLA. 175 



Distribution. — Carboniferous : Upper part of the Lower-Limestone series, Law, 

 Dairy. Lower part of lower-Limestone series, Crawfield, Kilbirnie. From shale 

 above the Linn-Spout limestone at Stacklawhill, Stewarton. (J. Smith, J. Bennie.) 



Order. — Calcispongi^. 



Family. — Pharetrones. 



Genus. — Peronella, Zittel. 



1878. Studien iiber fossile Spongiea. Abhandl. derk. bayer. Akademie der "Wiss., 

 CI. ii, Bd. xiii, Abth. ii, p. 120. 



Syn. — Scyphia, Siphonia, Spongia, Auct. ; Eudea (in part), Hippalimus (in part), 

 D'Orbigny ; Siphonocoelia (in part), Polycoelia (in part), Disccelia (in part), Steno- 

 coelia, Fromentel ; Pareudea (in part), Motion; Dendroccelia, Laube ; Coeloconia, 

 Dyoconia, Gymnorea, Pliocoelia, Siphonocoelia, Lcenoccelia, Pomel ; Spongites, 

 Derniispongia, Radicispongia, Quenstedt. 



Sponges simple or branching from buds, the individual forms are cylindrical, 

 with a simple tubular cloaca which extends to the base of the Sponge. The basal 

 portion occasionally with a smooth or corrugated dermal layer, the upper portion 

 of the Sponge usually without a special membrane over the fibres. The circulation 

 appears to have been carried on through the irregular interspaces of the skeletal- 

 fibres, and special canals are not indicated in the skeleton. The anastomosing fibres 

 form an irregular meshwork ; they consist of three- and four-rayed spicules, of large 

 and moderate dimensions, which are disposed approximately in the axial centre of 

 the fibre, and are surrounded by similar but smaller spicules. Uniaxial spicules 

 may possibly be also present. 



This genus is stated to make its first appearance in the Devonian formation, and 

 Prof. v. Zittel has referred to it Scyphia conoidea, Goldfuss, and Scyphia constricta, 

 Sandberger. The spicular structure of these forms has, however, not yet been 

 recognised, and it is not until reaching Jurassic strata that we find examples of 

 Peronella in which the spicular structure of the fibres has been preserved. In 

 calcareous shales of Carboniferous age from the East of Scotland Mr. James Bennie 

 has found detached spicules, which in form, size, and mineral structure, correspond 

 very closely with spicules of Peronella, and I therefore refer them provisionally to 

 this genus. 



