Or 
bo 
COELENTERATA—SPONGIAE CLASS I 
Saccospongia, Ranft. Silurian. Megalithista, Zitt. Upper Jurassic; Nattheim. 
Doryderma, Zitt. (Fig. 64). Sponge-body cylindrical, simple or branching, 
pyriform or compressed, with a number of larger canals running parallel 
with the body axis, and numerous smaller radial canals. Skeletal elements 
e 4 - large, bent, and 
divided into two 
or more simple 
branches. Dermal 
spicules in the 
form of three- 
fluked anchors. 
Upper __ Cretace- 
ous; Northern 
Germany, Eng- 
land, and France. 
According to 
Hinde, also Car- 
La ) boniferous. 
ae Carterella, 
Doryderma dichotoma, Roem. sp. Upper Cretaceous. a, Sponge, natural size ; Zitt. Cretaceous. 
b, Dermal layer, 2/;; ce, Bundle of skeletal elements, 1/;; d, Skeletal element and : Ore 
several dermal spicules with fureate, anchor-shaped head-rays, %0/}. Ison h aphi nea, 
j Zitt. Sub-cylin- 
drical, pedunculate, with wide cloaca reaching nearly to the base. Skeletal 
elements large, slightly bent, rod-shaped, inflated at the ends, rarely dichoto- 
mously branching. They are associated in bundles, and so interlocked at their 
extremities as to form an open meshwork. Cretaceous. J. terta, Roemer sp. 


WHE \\> 
14 CAA 
J Varlgy \ 
chy 7 9, 

Sub-Order E. RHIZOMORINA. Zittel. 
Skeletal elements small, composed of four or of three principal rays, or simple and 
irreqular, with numerous projecting spines or tubercles ; axtal canal simple or branching. 
Dermal spicules monaxons, tetraxons, or similar to those of the skeleton. Chietly 
Jurassic, Cretaceous, and Recent. 
? Nipterella, Hinde. Cambrian. 
Cnemidiastrum, Zitt. (Cnemidium, p. p. Goldf.), (Fig. 65). Turbinate or bowl- 
shaped, with deep cloaca. Walls thick, perforated by numerous radial canals 
disposed in tiers one over another, thus forming vertical fissures which often 
divide toward the exterior. Skeletal elements irregularly branching, entirely 
beset with blunt, spiny processes. Abundant in the Upper Jurassic Spongiten- 
kalk of South Germany, the skeletons being almost invariably replaced by 
calcite. (. rimulosum, Goldf. According to Hinde also present in the 
Carboniferous Limestone of Ireland. 
Hyalotragos, Zitt. Bowl, plate-, or funnel-shaped, with short peduncle. 
Depression in summit perforated by the ostia of numerous short canals. Ex- 
ternal surface finely perforate, or covered by a smooth or wrinkled dermal layer. 
Skeletal elements irregular, withnumerous branches beset with points, but with few 
spines. Very abundant in Upper Jurassic Spongitenkalk. 7. patella, Goldf. sp. 
Platychonia, Zitt. Leaf- or ear-shaped, irregularly undulating, covered on 
both surfaces with fine pores. Skeletal elements resembling those of /Hyalo- 
tragos. Upper Jurassic. P. vagans, Quenst. sp. 
