ORDER IV SILICISPONGIAE—HEXACTINELLIDA 61 
Family 6. Maeandrospongidae. Zittel. 
Sponge body consisting of thin-walled, intricately labyrinthine, and partially 
amalgamated tubes or foliae, which form tuberous, pyriform, beaker-shaped, or bush- 
like branching stocks. Be- 
tween the tubes are cavities 
and interstices of consider- 
able size, which constitute 
the so-called intercanalicu- 
lar system. Four canals 
faintlydeveloped. Dermal 
layer absent, or represented 
by a continuous silicious 
superficial skin. Abun- 
dant in the Cretaceous, 
and also represented Plocoscyphia pertusa, Gein. Greensand (Cenomanian); Banowitz, Hungary. 
by numerous” recent “@, Fragment in natural size; b, Dermal layer, five times enlarged ; c, Skeleton 
& of interior, 12/; ; d, Outward portion of skeleton, 12/;. 
genera. 
Plocoscyphia, Reuss. (Fig. 81). Clamp-like or bulbous stocks consisting of 
labyrinthic, anastomosing tubes or foliae. Walls of tubes thin, perforated by 
numerous small ostia, Latticed skeleton, intersection nodes solid or perforate. 
Cretaceous. . 
Becksia, Schiiiter (Fig. 82). The thin walls of the shallow, beaker-like 
sponge are composed of vertical tubes having a radial disposition and fused with 
one another along 
the sides. Between 
the tubes are large 
interstices ; near the 
base the tubes de- 
velop hollow, spinous 
processes. Lattice 
skeleton very regu- 
lar, exactly similar 
to Coeloptychium. 
Upper Cretaceous ; 
Westphalia. 
Tremabolites, 
“Zitt.; LHtheridgia, 
Tate ; Zittelispongia, 
Sinzoff, ete. Upper 
Becksia Sokelandi, Schhit. Quadratenkreide : Coesfeld, Westphalia. A, Sponge Cretaceous. 
body, 1/5 natural size; 0, Ostia of radial canals ; f, Hollow, root-like processes of Y ee a 
wall. B, Skeleton, 59/;. : Camerospongia, 
di@rb: (ig: 83). 
Globular, sub-globular, or pyriform. Upper half of the body enveloped by 
smooth silicious skin, and with large circular depression on the summit ; lower 
half marked by undulating ridges and furrows, and passing gradually into a 
stem. Interior of sponge body consists of thin-walled, labyrinthous tubes. 
Upper Cretaceous. 
Cystispongia, Roem. (Fig. 84). Like the preceding, but with dense silicious 


