[MATTHBwl STUDIES ON CAMBRIAN FAUNAS 111 



COLEOIDES, Walcott. 



COLEOIDES TYPICALIS, Walc. (PI. Vf., fig. 2). 



Coleoides typicalis, Walc, Proc. National Museum, vol. xii., 1899, p. 37, figure in 



" Olenellus Zone," pi. Ixxix., fig. 6 and 6a. 

 Coleoides typicalis, Walc, Nat. Hist. Soc. N.B., Bull. No. xviii., p. 192. 



Examples which appear to agree in all respects with the object 

 which Mr. Walcott has thus named, occur at Smith Sound. 



Sculpture. — The striaj are very fine, and as figured in plate Ixxix., in 

 most cases incline to the right, though one was observed in which the striœ 

 inclined to the left. Those on the larger specimens seem quite as close and 

 fine as those on the more slender pieces. 



Size. — The largest fragments met with have a diameter of 1|- mm. 

 and a length of 6 mm., other narrower ones have a length of 10 mm. 

 About a dozen pieces of those rods have been seen. 



Mode of occurrence. — Coleoides comports itself exactly in the same 

 way as Hyolithellus ; the pieces ai-e occasionally in close parallelism with 

 each other, and again they occur in slightly radiating groups ; and 

 elsewhere are scattered in and near the tubes of Hyolithida. Whatever 

 the tubes of Hyolithellus may prove to be, these objects will go with 

 them. Examples of Coleoides occur in which the striation is so faint 

 that it is difficult to distinguish them from those of Hyolithellus. 



OETHOTHECA, Novak. 



Orthotheca pugio. (PI. VI., tigs. Aa to e). 



Orthotheca pugio, Nat. Hist. Soc N.B., Bull, xviii., p 193, pi. ii., figs. 4a to e. 



An elongated, thick-shelled species, somewhat flattened on the dorsal 

 side ; this side is more strongly arched longitudinally than the ventral 

 side, causing the tube to have a considerable curve towards the apex. In 

 an example, 27 mm. long, the cord of the arc of the dorsal side is 1 mm. 

 long. The apical part of the tube frequently has one or more septa, 

 concave on the upper side, usually placed where the diameter is IJ or 2 

 mm., but sometimes where it is 3 mm. ; the shell may be decollated below 

 the lowest septum. The taper of the tube varies from 1 to 7 in the apical 

 part, to 1 in 9 in the distal part of the tube ; often it is more regular at 

 about 1 in 8. Apical angle about 7°. 



Sculpture. — There is a fine granulation over the whole surface 

 through which in places, especially toward the aperture, obscure trans- 

 verse striation can be seen with a lens, and more commonly on the 

 ventral side. The striae are slightly deflected downward at the rounded 

 lateral angles, showing the mouth of the tube to be somewhat emarginate 

 there. 



