GENUS TINOPOEUS: HISTOEY. 557 



The extension of spines from the whole surface of the disk, in the mode represented in 

 Fig. I. A, may in like manner be regarded as a sort of " running-wild " of the supple- 

 mental skeleton. 



Genus TINOPORUS. 



208. A more remarkable example could scarcely be adduced, of the necessity of a 

 thorough examination of the internal structure of the skeletons of Foraminifera as a 

 guide to the determination of their true affinities, and of the danger of relying upon 

 external characters alone, than that presented by the type I am next to describe under 

 the name Tinoporus ; certain forms of which present so strong a superficial resemblance 

 to many specimens of Calcarina, as to be unhesitatingly associated with them by every 

 one who has not had his attention directed to the minute features of difference they 

 present; whilst the plan on which it is constructed will be found to be essentially 

 diverse. 



209. History. My reason for adopting this name is as follows. In the ' Conchyliogie 

 Systematique ' of DENTS DE MONTFORT (Paris, 1808), there is described and figured * 

 under the name of Tinoporus baculatus a small polythalamous body, which he seems to 

 have distinguished from the other varieties of Nautilus (Calcarina) Spengleri figured by 

 MM. FICHTEL and MOLL, partly by the fewness of its spines, and partly by the difference 

 of its structure as displayed in vertical section. And although his figure and description 

 are alike inaccurate (the former, as has been pointed out by Messrs. W. K. PARKER and 

 T. R. JONES f, being partly drawn from specimens of Calcarina), yet as I can scarcely 

 doubt that he had before him a specimen of the type I am about to describe, I think 

 it right to retain the distinctive designation he conferred upon it. The following is 

 DE MONTFORT'S characterization of the genus : " Coquille libre, univalve cloisonnee 

 et cellulee, spiree et lenticulaire ; tet granule exterieurement ; bouche semi-lunaire, 

 placee vers la circonference et sur un des cotes ; dos carene, arme de quatre pointes au 

 plus ; les deux centres bornbes et releves." Of the species T. baculatus, which served 

 as his type of the genus, and of which he gives the fourth variety of the Nautilus 

 Spengleri of FICHTEL and MOLL as a synonym, he says : " Cette coquille, qui pour nous 

 est la tete (type 1) d'un genre nouveau et assez nombreux, ressembleroit a la nummulie 

 ou camerine tuberculee et criblee, si elle n'etoit armee de trois pointes obtuses. Ces 

 pointes sont interieurement sillonees et tuberculees a la maniere de quelques tubipores : 

 la bouche de la coquille, placee sur un des cotes, est tres remarquable, en ce qu'elle est 

 petite et formee en demi-lune : la spire est cachee et interieure. Les auteurs allemands 

 que nous avons cites dans notre synonymie, y compterent au moins quatre-vingts cellules. 

 Nous avons fendu cette coquille a demi par le milieu, afin de faire apercevoir la con- 

 struction de I'interieur, qui, cellulee sur divers plans, nous conduit naturellement aux 

 nummulies, mais elle en differe par ses bras ou pointes, qui sont constans, quoique leur 



* Toine i. p. 147. t Aiiuals of Natural History, Series 3. vol. vi. p. 34. 



