ILLUSTEATIONS OF THE FAUNA OF THE ST. JOHN GEOUP. 



99 



common in some layers of the Div. Sd shale. It differs from the type in having more as- 

 cending branches to the hydrosoma. 



Dr. Ami has the following annotations on the specimens sent to him: "The five 

 specimens referred to this species, with or without doubt, and marked by me in red A, B, 

 C, D, E, respectively, appear to me to belong to two distinct forms. A, D and E repre- 

 sent one form or species, and B and C the other. The former a stouter and larger one, 

 the latter a rather more slender one, and more akin to the type of Hall's species. 



"The type oï Diplograptus nilidus (Geol. Surv. Can. Dec. II., PI. I., fig. 7) measures 

 hvelve hydrothectc in the space of ten millimetres, and the height or breadth of the poly- 

 pary at the tenth hydrotheca from the sicula or initial point is 1'25 mm. 



"The measurements of the different forms are as follows : — 



"A. There is no sicula or initial point in the 18 or 20 stipes preserved on this slab of 

 shale. The hydrotheca? are set very obliquely, and their position must evidently be due 

 to distortion by pressure, and differs [?] essentially from the type in this particular. D and 

 E may possibly be fragments of Didymograplvs, but resemble also possibly stipes of Tetra- 

 graptus in a broken condition. 



" B and C. These two forms are more akin and closely related to the type specimens 

 as described by Hall, from the Point Levis beds. They are much more slender than either 

 A, D or E, and in dimensions as well as in leading characters shown, they agree very 

 fairly well with D. nUidus, Hall. The divergence of the stipes, or ' angle of divergence ' 

 proper as shown in B and C may probably also be due to pressure. There are not seen 

 any of the apertural spines seen in the type specimens of D. nilidus, Hall." 



DiDYMOORAPTUS INDENTUS, Hall. 



Graplolithus indentus, Hall, Can. Org. Rem. Dec. ii., p. 74, PI. i., fig. 20. 



Only one example of this species has been found, of which Dr. Ami says : 

 may probably be D. indenlvs, Hall. Very closely allied to the type specimen." 

 Horizon and Locality. Same as the three preceding. 



This 



' In cases where the sicula is present; in broken stipes, the average dimension is taken in the stipe named. 



