312 KEPOET— 1892. 



1852. Genus Bitubigera, d'Orb. {^^Idmonea (pars), Philippi). 

 ' Terr. Cret.,' p. 748. 



This genus was founded by d'Orbigny for Idmonea sp., Philippi, 

 derived from No. 26 stage, Falunien, for the location of Bitubigera 

 (^Idmonea) biseriata, Phil. (1844). Wo Cretaceous species is recorded by 

 d'Orbigny. Marsson, ' Bryoz. Weiss. Schreibkr. Riigen,' p. 31, adopts the 

 genus for the inclusion of one species, B. compressa, Mars., pi. iii., fig. 1. 

 The species now recorded is different from either of the forms cited, bui 

 it is very rare in the Chatham Chalk. 



63. Bitubigera cribriformis, sp. n. 



The zooecia of this species are disposed, Idmonea-like, in two series 

 obliquely over one-half the zoarinm. The interspaces between the rows 

 and the slightly rounded reverse are of a cribriform character. Judging 

 from his figures, Marsson's depicted characters are quite plain. 



I have seen a British example closely related to the above chai-ac- 

 terised as Idmonea gradata, but I have followed Marsson in the recognition 

 of d'Orbigny's genus. 



1850. Genus Desmepora, Lonsdale, Dixon's ' Gaol. Sussex,' p. 281. 



64. Desmepora semicylinrlrica (= Idmonea semicylindrica, Romer), 



' Gcol. Sus.,' p. 281, pi. 18a, fig. 6. 



There are sliglit variations in the size of fasciculaj in young and pld 

 examples of this abundant' species. Idmonea semici/Uudrica, Rom., 

 d'Orbigny regarded as a Trwncatula ('Terr. Cret.,' p. 10-"»4). 



In Mr. Gamble's collection of Chatham Polyzoa there is a very beau- 

 tiful example of this species, silicified and nearly transparent, Avhich 

 shows the inter-zooecial and reverse reticulation and all the other cha- 

 racters of the species in the most perfect manner. 



1852. Genus Semiottis, d'Orb. (Osculipora (pars), d'Orb., 1847), 

 'Terr. Cret.,' p. 1048. 



65. Semicytis rugosa, d'Orb. = Osculipora rugosa, d'Orb., op. c, p. 



1049, pi. 795, figs. 1-7. 



D'Orbigny gives the following localities where this species has been dis- 

 covered : — Fecamp (d'Orb.) ; Folkestone (d'Orb.) ; Carancy (Defrance) ; 

 and I now add Chatham, where it is somewhat rare. 



m. Semicytis sp. (Francqana ?, ' Terr. Cret.,' p. 1052, pL 794, fig. 14). 



Of this citation I am rather doubtful. I have only seen the basal 

 part of a zoarium, which resembles the basal part of d'Orbigny's figure. 



1850. Genus Homceosolen, Lonsd., Dixon's ' Geol. Sussex,' p. 307. 



It is very certain that some of the species characterised by d'Orbigny 

 belong to the genus Honiwosolen, as defined by Lonsdale. The three 

 species of Truncatida of Hagenow, T. filex, T. truncata, and T. repens, are 

 relegated by Marsson (' Bryoz. Weiss. Schreib. Riigen,' p. 37) to the genns 

 Osculipora, d'Orbigny, under which name two of Hagenow's species are 

 placed by him, as 0. truncata = lietepora truncata, Goldf, and 0. repens 



