134 M. K. A. Zittel on Fossil Galcispongue. 



concentrically wrinkled surface ; vertex consisting of a curled, 

 rather coarse tissue of anastomosing calcareous fibres, which 

 also composes the interior of the sponge-body. The circula- 

 tion of water could only take place in the interstices of the 

 skeleton. 



In this genus I have been unable to detect spicules in the 

 calcareous fibres. All the thin sections which I have prepared 

 of specimens from St. Cassian or from the Seeland Alp ex- 

 hibit a crystalline-radiate structure. 



By Laube several true Bryozoa were united with Leiofun- 

 gia, Cribroscyphia, and Actinofungia ; and Pomel also refers 

 a true Bryozoan (Catenipora spongiosa, Klipst.) to Aulaco- 

 pagia. All these forms may easily be distinguished from the 

 fibrous sponges by their tubular structure. 



I am acquainted with the genus Leiospongia only from the 

 Alpine Trias. 



1. Achilleum milleporatum, Miinst. Beitr. iv. Taf. i. fig. 5„ 



2. Achilleum radiciforme, Miinst. ib. Taf. ii. fig. 20. 



3. Achilleum verrucosum, Miinst. ib. Taf. i. fig. 1. 



4. Achilleum subcariosum, Miinst. ib. Taf. i.'fig. 2. 



5. Achilleum reticulare, Miinst. ib. Taf. iv. fig. 4. 

 Non Leiofungia reticularis, Laube, St. Cass. Taf. ii. fig. 8. 



6. Achilleum rugosum, Miinst. ib. Taf. i. fig. 3. 



Family 4. Sycones, Hackel. 



Wall regularly composed of straight unbranched canals or 

 tubes, directed radially towards the axis of the stomach 

 (radial canals, radial tubes). Skeletal spicules regularly 

 radially arranged ; dermal and gastral skeletons separated 

 from the parenchyma-skeleton. 



Protosycon, Zittel. 



Seyphia p. p., Goldf. 

 Siphonocceha p. p., From. 



Sponge simple, cylindrical or clavate, narrowed below, with 

 a wide tubular central cavity extending to the base. The 

 wall consists of hollow radial cones, placed in layers one 

 above the other, with their bases towards the central cavity 

 and their apices directed outwards. These hollow cones, 

 opening inwards, produce, on the wall of the central cavity, 

 numerous ostia, arranged in longitudinal rows, and leading 

 into the hollow cones. As the latter are narrowed outwards 

 and terminate in a truncated head, conical interspaces, but 

 pointed inwards, are formed between ; and if both the hollow 

 cones and interspaces are filled with rock matter, it appears 



