222 
EXTALOPHORA. 
Museum collection (D. 941), which M. Pergens has identified as 
E. prohoscidea, the diameters of the zooecia and apertures are 
respectively *16 mm. and *21 mm.; these proportions agree more 
nearly with M. Pergens’ figures for E. ramosissima (*16 mm. and 
■26 mm. respectively) than with those he gives for E. prohoscidea. 
The ^N'eocomian specimen figured by d’Orbigny as E. iconensis 
(Bry. Cret. pi. 616, figs. 12-14) appears from the figure to have 
finer zooecia than E. virgula \ but as d’Orbigny states that the 
branches are ’5 mm. in diameter, his figure is magnified 10 dia., 
and the apertures are about *1 mm. in dia., and the length of the 
exposed portions of the zooecia from 1 to Pomm. They are 
thus shorter than in E. pergensi, which resembles E. iconensis 
in appearance ; the latter may he regarded as the Xcocomian 
representative of the form suhgracilis. 
E. carantina, Orb., is regarded as a synonym by von Reuss 
(1874); hut the grouping of the apertures into irregular nodes 
makes E. carantina a nearer ally of E. geminata^ or possibly even 
of Peripora. The Pustulipora nana, of von Hagenow, is a suhspiral 
form, and is included as a synonym in deference to the opinions of 
Hamm and Pergens. E. filiformis, Orb., is the same as P. nana. 
The Bidiastopora rusiica, Orb., appears to he only a flattened 
branch of E. virgula. The variety alter nata is accepted for a very 
primitive form, which d’Orbigny figured as Entalophora alternata. 
He subsequently transferred this species to Filisparsa, although 
on the very same figure he had founded a new species, Idmonea 
subalternata. Pergens includes this species in Idmonea ; but the 
apertures are isolated and irregular, and not in transverse series, so 
that the affinities are Entalophoridan and not Idmonian. 
Entalophora incerta, Yine, was described as having bulging nodes, 
a character suggestive of Peripora^ but it was subsequently included 
by Yine in E. raripora. 
The Entalophora variegata, of d’Orhigny, is, according to 
M. Pergens,^ one of the Cheilostomata ; in that case the original 
figures^ are very misleading, for they suggest that the species is 
an Entalophora^ closely allied to, if not identical with, the typical 
form of E. virgula. iSome specimens in the collection fiK)m 
1 Pergens: Eevision, p. 374. 
2 D’Orbigny: Bry. Cret. p. 792, pi. 622, figs. 18-21. 
