FOSSIL SPONGES. 
Spong. 
occur in the Upper Greensand at Warminster, Wiltshire, as comparev 
with that of the Lithistidcc of the same deposit, proves the originally 
calcareous nature of their spicules, and that Pharetrospovgia strahani, 
Sollas, as found in the Upper Chalk of Kent and Sussex, shows the same 
fact with regard to its spicules. He describes some new species from the 
Upper Greensand, Warminster, whose structure appears to him to further 
enforce these views (see infra). 
Steinmann, (20), classifies the known Pharelrones as follows, provision- 
ally, including various new genera and species, chiefly on the external 
characters and coarser anatomy of the internal cavities and skeleton ; the 
spicules are seldom described : — 
. Suborder i. Sphinctozoa. Pharetrones with segmented skeleton. 
Fam. 1. Sphcerocolidce. No central tube ; osculum single, large, central, 
or multiple, either large surrounded by small, or small only. Genera: — 
Sollasia, g. n., p. 151. Based on S. ostiolata, sp. n., pi. vii. fig. 3, from 
Carboniferous Limestone, Asturias. 
Thaumastocoslia , g. n., p. 153. Based on T. cassiana , sp. n., pis. vii. 
fig. 5, viii. fig. 3, ix. fig. 5, from strata containing Trachyceras aon , near 
St. Cassian. 
Celyphia , Pomel, C. submarginata, Munster, p. 158, pis. vii. figs. 8-10, 
ix. fig. 3. Synonyms given. 
Sphceroccelia , g. n., p. 162. Based on Thalamopora michelini , Simono- 
witsch, pi. vii. fig. 4, from Cenomanian, Essex. 
Fam. 2. Sphcerosiphonidai. Distinguished from Sphcerocolidm by the 
presence of a more or less closed central tube. No tissue filling the in- 
terior of the segments; wall traversed by straight or slightly curved 
canals; a central osculum. Genera: — 
Barroisia , Munier-Chalmas. Includes B. anastomosans , Mantell, pi. viii. 
fig. 1, Diseocodia helvetica , De Loriol & Gillieron, pi. vi. figs. 5 & 6, ix. 
fig. 1. 
Enoploccelia , g. n., p. 166. Based on Scyphia armata, Klipsteiu, pi. vi. 
fig. 4. Distinguished by a compact epidermis and oscula with projecting 
margins. 
Thala>nopora } Itoemer. 
Amblysiphonella , g. u., p. 169. Based on A. barroisi, sp. n., Carboni- 
ferous Limestone, Asturias. 
Sebargasia , g. n., p. 171. Differs from Barroisia probably in the larger 
number of connecting tubes, and in tho different manner of origiu 
of the central tube. S. carbonaria , sp. n., Carboniferous Limestoue, 
Asturias. 
Fam. 2. Verticillitidce. Differs from the preceding family by the pre- 
sence of an anastomosing network within the segments. 
Genera: — Colospongia, Lbe., C. dubia, Munster, pi. vi. fig. 3, Verticil - 
lites , Dfr., V. cretaceus, Dfr., pi. viii. fig. 2. 
Fam. 3. Cryptocoeliidce. Based on Cryptoccelia , g. n., p. 176, C. zitteli, 
sp. n., pis. vii. fig. 1, viii. fig. 5, ix. fig. 4. The spicules resemble those of 
A Icyonaria. 
Suborder ii. Inozoa. Pharetrones with a continuous, i.e. unsegmented, 
skeleton. 
