ORDER IV 



8ILICI8PONGIAE HEXACTINELLIDA 





and merely indicated l>y cavities. The nmiv important f> il form- are divided 

 into the following familic-. 



Family 1. Craticularidae. llauli. /'>/- //,/,/,. ]>. j... Zitt.-l M..H Srlmi/.-. 

 Cup-sliapril, i-f/linili-ii'iil, liriiH'-liiitif. ) jl<itt<,,l >y/,//,^ v. ,Syi/V///.//- /- 



aiirf'tii-i- irifliuiif ilinfinrf 



outer skeletal lat/rr, <nnl 

 occasionally covered 



iritli it i/fliniff trt'li of 



cemented spicules. 

 Canals simple, UMly 



1> mi unit iii<! in flu- 



Jurassic. 



///////'. //>// y//v,//-/7r'/ /'// '/ /A/'7.v/////-/ /,/' ///, 



Upper Jurassic; Strt'itlicr^, Krancuiiia. 

 1 - - :, natural sixc ; l>, Enlarged jiortiuii ol' ouli-r surlan- \vitlmut di-rmal 



n minimi n 



Tremadictyon, 



Zitt. (Fig. 73). Cup-, 

 plate -shaped, or 

 cylindrical, with wide 

 cloaca. Canal-open- 

 ings on both sides 

 in alternating rows. 

 Base nodular; ex- 

 terior veiled over Fio 73 

 with delicate net- Tremadictyon reticuiat,, Goi.if. sp." ' 



WOrk Of amalgamated ". *P<>i',-<'. - :, natural Size ; /., Knlar-.-d . 



. . ,. layer: c, Portion with well-preserved dermal layer, :; i : </. Skeleton, '-' \. 



hexactins, extending 



even across canal pores. Skeletal framework with more or less 



cubical meshes. Very 

 Upper Jurassic. 



Craticularia, Zitt. (Fig. 74). Funnel 

 shaped, cylindrical, or flattened : simple, 

 or branching. Canal-openings on both 

 surfaces either round or elliptical, and 

 regularly distributed in vertical and 

 liori/ontal rows. Canals short, ending 

 blind. Jurassic, Cretaceous, and 

 Miocene. 



Sporadopyle, Zitt. Cup- to funnel 

 shaped or conical, occasionally branch- 

 ing. Canal-openings on outer surface 

 irregularly distributed, <>r arranged in 

 quincunx; on cloacal surface in vertical 

 rows. Upper Jurassic. 

 Goldf. sp. 

 SpJienaulax, Zitt., Ferrucocoelio, Etall, etc. Jurassic. 



I'riitiriilnriii 



Muggendorf, Franconia. 



Upper .1 

 natural 



", Sponge, !/ 

 I, Latticed skeleton, 1% ; c, Thickened dernial layer. 



Family 2. Ooscinoporidae. Zittel. 



Calycoid, beaker-like, lobate, branching, or stellately concolntud *p<t ;/><, ////// flint 

 walls perforated on both side* by mimci-mi* <-<in'il-in'tiiinj* <irr<i />>/<'>/ in lf> -unit in;/ 



