FAUNA OF THE ST. JOHN GROUP. 51 



Agnostus appears in Salter's A. trinodua, in which the lobes of the rachis are arranged as 

 in the Acadian species here described, but the shape of the rachis is qviite different. 



Arranged chronologically these several species would fall in the following succes- 

 sion: A.fallax, vir, bisectus, Siden bladhi, Galba, glabralus, trinudus} 



PARABOLINA, Salter (1849). 



Parabolina SPINULOSA. Wahl. (PI. XIII, figs. 5 a-d.) 



1821 — Eniomostracites spinvJosus. Wahl. ' Pet. Tell. Ruec.,'^p. 38. Tab. i, fig. 3. 



1822— Paradoxides spinvioms. Brongn. 'Crust, foss.,' p. 32. Tab. 4, figs. 2 and 3. 



1827 — Ohnus spinuloms. Dalm. ' Om Palœad,' p. 250. 



1838— rn/'jM(i's gibbosus. Wahl- var. ' Bœck, Gfea. Norv.,' p. 143. 



1843 — Paradoxides spinuloses. Burm. ' Org. d. trilob.,' p. 80. 



lS5i— Parabolina spinulosa. Ang. ' False. Scand.,' p. 46. T. xxv, fig. 9. 



18b7—Olenus spimdosiis. Kjerulf. ' Geol. d. sudl. Norw.,' p. 284. 



18(J5 — Parabolina spinulosa. Kjerulf. ' Veiviser,' etc., p. 2. 



A few well marked examples of this species occur in a limestone lentile with Orthis 

 lenticularis about one hundred feet from the base of DiAÙsion 3. The most important parts 

 of the body are preserved and justify the reference to this species. 



A pygidium of a young individual shows shorter spines than those of the adult of 

 the European form of this species. 



Horizon and Localili/. — Black shales of Div. 3 a at Germaine St., St. John. 



Parabolina heres. Brogger. 



Parabolina hires. Brog. ' Die Silurischen, Etagen 2 und 3,' p. 101. Tab. i, fig. 13 a-d. 

 Var. lata n. var. (PI. XIII, figs. 6 a-f.) 



This form is a near relative of Parabolina heres, Brogger, but differs in the following 

 respects : — 



Headshield — In this the glabella [is much broader in proportion to its length, and 

 the fixed cheek also is broader behind. Movable cheek — This in form resembles that of 

 P. spinulosa rather than P. heres, and the posterior border is at right angles with the mar- 

 ginal fold and spine. 



Pygidium — This has four joints in the rachis and only three spines on each side at 

 the border ; the joints of the rachis appear to be devoid of spines. 



Hypostome — It is in this part that the most important difference consists. If we are 

 right in referring here a hypostome found with this species, it differs considerably from 

 the other hypostomes of this genus known, but among those hypostomes it is nearest to that 

 of P. heres: Two examples are known, neither of which are perfect. The form is trapezoidal, 

 with a short spine on each posterior corner. The front is not complete, but appears to be 

 broadly oval, owing to the projection of the lateral lobes ; these are comma shaped, and 



' Since writing the above I have noticed that Dr. Brogger has written on the relationship of these species. 

 ' Die Silurischen Etagen 2 und 3. Tab. ii, fig. 13 a. 



