52 F. Chapman — Gault Hyaline Foraminifera. 



■wax impression, is about 2 mm. wide. Each unworn tooth is 

 strongly curved, or rather crooked, with an acute somewhat re- 

 curved point. The concavity of each tooth is directed towards the 

 end where they are least worn. The cavities, left by the teeth which 

 have fallen out, show that these teeth were provided with a very 

 distinct ridge on each side, and they appear to have been flattened 

 from before backwards. 



An examination of the broken surfaces with a lens reveals a very 

 vascular condition of the base, and large vessels pass from this into 

 each tooth. No division can be traced between the bases of the 

 teeth, which are evidently firmly united to each other. 



Compared with Onycliodiis angliciis and 0. arcticus, the present 

 specimen differs in the more uniform size of its teeth, the longest 

 of which is not half the length of the most perfect tooth in the 

 former species, from which it also differs in the greater curve, and 

 non-involution of the base; and further, its teeth have distinct 

 lateral ridges and no central cavity. 



The uniform size of the teeth in the Forfar specimen agrees better 

 with the American forms, but they are much smaller than in any 

 one of the three species described by Pi'of. Newberrj', and are of 

 a different shape. In 0. Ortoni the teeth are said to be sunk in the 

 base " as posts are planted in the ground." 



British examples of this genus are so rare that even such frag- 

 ments as that above described may well receive specific distinction, 

 and I propose to name it Omjchodus scoticiis. 



The following are the species of Onychodns now known : — 



0. sigmoides, Newberry. Corniferous Limestone (Lower Devonian), Ohio. Monog. 



U. S. GeoL Surv. vol. xvi. p. 56, 1889. 

 0. Sop/dnsi, Newberry. Chemung Group (Upper Devonian), Delaware Co., New 



York. Ibid. p. 99. 

 0. Ortoni, Newberry. Huron Shale (Upper Devonian), Franklin Co., Ohio. 



Ibid. p. 71. 

 0. aitylicus, Smith Woodward. Lower Old Red Sandstone Passage Bed, Ledbury, 



Herefordshire. Geol. Mag. Vol. V. 1888, p. 500, and Cat. Foss. Fishes, 



Brit. Mus. part 1, p. 393, 1891. 

 0. arcticus, Smith "Woodward. Lower Devonian, Spitzbergen. Geol. Mag. 



Vol. VI. 1889, p. 499; and Ann. Mag. Nat. Hist. vol. viii. 1891, p. 1. 

 0. scoticus, Newton. Old Eed Sandstone, Forfar. 



m. — Some New Forms of Hyaline Foraminifera from the Gault. 



By Frederick Chapman, 



(PLATE II.) 



IN the course of investigations amongst the Microzoa from the 

 Gault of Copt Point, Folkestone, some Foraminifera came under 

 my notice, which are hyaline representatives of the usually arenaceous 

 type Wehhina. These forms are remarkably similar in external 

 appearance to those of the arenaceous group, but microscopical 

 examination of the test iinder a high power reveals the finely 

 tubulated structure characteristic of the hyaline type. 



It must, however, be borne in mind that the isomorphous genera 

 in the three groups of the Foraminifera based upon shell-structure 



