so KOYAL SOCIETY OF CANADA 



Cove, New Brunswick. I'liistern Canada, enabled him two years ago to 

 recognize the free-cheek and pygidium, and now in this Uttle species we 

 have the thorax as well. This species is of unusual interest, as it combines 

 characters found in .several associated genera, thus it has the pleural groove 

 of Zaiaiitlioides, but the dorsal suture and to some extent the glabella of 

 Balhyuriscus ; the long eye-lobe and very narrow fixed cheek recall 

 Conocephalites, sens, strict., but in other respects it is far removed, and 

 will be classed with Olenidtu. 



If one may gather instruction from the position and length of the 

 eye-lobe, coui-se of the suture, form of the glabella, etc., the Acadian 

 species is the mo.st ])rimitive.' The Swedish comes next, and this species 

 of Mt. Stephen is the most advanced typo of Dolichometopus. 



BATllYURISCUS, Meek. 

 Bathyuriscus iiowKLM, Walcott. 



Bnthyuriscus Hoivelli, Wale, U. S. Geol. Surv., Bull. 30, p. 216, pi. xxx., figs. 2, 2a. 

 Embolimus rotundattis, Roem., Acad. Nat. Sci., Phil., Proc, 1887, p. 16, pi. i., fig, 4. 



Dr. Roeminger has figured two examples of this species, which 

 together re])resent all the parts except the hypostome. The species is 

 remarkable for the expansion of the glabella in front and the peculiar 

 placing of the glabellar furrows. There is considerable variation in the 

 form of the glabella and the distinctness of the several furrows upon it, 

 but there appeal's to be only one species. 



As Dr. Roeminger remarked, there are nine rings in the thorax and 

 six in the pygidium, the ridges at the sides of the pleura are broad and 

 strong, and the furrows extend well out to the ends. 



The pygidium is usually without spines, but a few which appear to 

 belong to the species have a short spine at the anterior angle. 



Development of the young. — A small head of this species, 2^ mm. long, 

 was met with, but has probably been shortened by distortion ; the width 

 at the front is 2 mm. and behind, 5^ mm. In this head the glabella is 

 1^ mm. wide in front, 1|- l)ehind, and 2 mm. long. There is a spine on 

 the middle of the occipital ring. The youngest well-preserved heads 

 observed were 6 mm. long ; in these the glabella has a greater propor- 

 tionate width in front than in the adult; it is 4^ mm. in width in front, 

 2^ mm. behind, and the length is 5 mm. In the adult the proportions 

 are 10^, 9, 13 in one, 8^, 7, lU^ in another; these two are less club- 

 shaped than the majority of the head-shields, among which individuals 

 may bo found with a glabella proportioned 8, 4, lU^. In some of the 



• Trans. Roy. Soc. Can., 2d ser., vol. iii., sec. iv., p. 184, pi. lii., figs. 6a-d and 7a 

 and l>. 



