A MIDDLE CAMBRIAN FAUNA PROM BENNETT ISLAND 



11 



Gronwall (and possibly also Tullberg) seem to have identified with, young specimens of 

 A. glandiformis a form which is distinct from the latter and which in my opinion may be 

 identified with A. Utuherciilatus Ang. (see beloW). According to Gronwall (and Tullberg) 

 the cephalon of young specimens of A. glandiformis differs from that of adult specimens in 

 having a pair of distinct small basal lobes and, sometimes, a very faintly marked elongated 

 median ridge in its anterior part, i. e. marks distinctive of A. Utuberculatus. And the pygi- 

 dium figured by Gronwall and by him looked upon as a young specimen of A. glandiformis 

 belongs also to A. hituherculatus. Thanks to the courtesy of Dr. Ravn of Copenhagen, I have 

 had the opportunity of examining the said pygidium and found it to be identical with the Scanian 

 form here referred to the last-mentioned species. It is distinguished from adult as well 

 as young specimens of A. glandiformis by having an ovate (not sub-rectangular) outline, 

 the marginal rim narrower behind than at the sides, an elongated (not punctiform) median 

 tubercle, stronger arching, and a quite differently shaped doublure (see pi. IV, fig. 2 and 6). 



In Scandinavia A. glandiformis is restricted to the zone of Paradoxides fordihammeri. 

 It is common in Scania and Bornholm, very rare in Jemtland and Angermanland and, 

 according to Brogger, rare also in Norway. 



Agnostus hituherculatus Angelin 



[PL I, fig. 10 (11, 12?); pi. IV, fig. 4—6] 



1851 Agnostus hituherculatus, Angelin, Palaeont. Suecica, p. 6, pi. 6, fig. 2. 

 / 1902 Agnostus glandiformis (pars), Gronwall, Bornholms Paradoxideslag, p. 63, pi. 1, fig. 6. 

 Non: 

 1878 Agnostus hituherculatus, Broggeb, Paradoxidesskifrene ved Krekling, p. 59, pi. 6, fig. 9. 



This species has not hitherto been properly fixed. In his monograph on the Agnostidae 

 from Andrarum, Tullberg states that he was not able to find this species again, but his 

 description of A. glandiformis suggests that he possibly regarded cephala of A. hituherculatus 

 as young specimens of the former. 



In a few small pieces of Andrarum limestone belonging to the Paleozoological De- 

 partment of the Swedish State Museum there appear a couple of cephala and pygidia of an 

 Agnostus which agree with Angelin's figure of A. hituherculatus so 'well that they may be 

 identified with the said species. The cephalon is strongly arched, devoid of a marginal rim,^ 

 bearing in its anterior part a very faint, longitudinal ridge and having a pair of small but 

 distinct basal lobes. The pygidium is strongly arched and raised into a distinct elongated 

 tubercle; marginal rim extended at the sides. 



Among the Agnosti from Bennett Island there are a couple' of cephala and pygidia 

 which I would identify with A. hituherculatus. The cephalon figured, which is preserved in 

 limestone and consequently in full relief, agrees very well with the Scandinavian form, only 

 it is somewhat shorter than the latter. However, this difference alone does not seem to be of 

 specifically distinguishing value. The abundant material of^A. glandiformis from the Scanian 



1 AngeUn's description of A, hituherculatus is not in 

 agreement with Ids figure of it as regards the cephalon, 

 which, according to the figure, has no marginal rim, hut 



in the diagnosis it is said to he marginate. As far as I can 

 see, the figure may be right and the diagnosis wrong in 

 this point (owing to a misprint?). 



