OBOLIDiE. 483 



LiNGULELLA BILLINGSIANA (Whiteaves) . 

 Plate XXIX, figures 3, 3a. 



Lingula hillingsiana Whiteaves, 1878, Am. Jour. Sci., 3d ser., vol. 16, p. 226. (Described, see below, as a new species.) 

 Lingulella? billingsana (^\^liteaves), Schuchert (in part), 1897, Bull. U. S. Geol. Survey No. 87, p. 256. (Merely 



changes generic reference and spelling of Whiteaves's Lingula hillingsiana, cited above. Includes also reference 



to specimens now referred to Lingulella grandis.) 

 Not Lingula billingsana Whiteaves, Matthew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, p. 205. 



(Mentions "Obolus (Lingulella) bellulus" Walcott as the same as "Lingula billingsana.") 



The original description by Wliiteaves follows : 



Shell small, very slightly convex, compressed at the sides; outline elliptic ovate, narrowest behind; length nearly 

 twice the width; margin of the valves widening convexly and gradually from the beaks to the center, or a little 

 beyond it; front narrowly and evenly rounded. Surface marked by fine concentric striations and faint radiating 

 lines. Internal markings unknown. Length, about two lines and a half; width, one line and a half. 



Observations. — Through the courtesy of Prof. J. F. Whiteaves I have been able to study 

 the type specimens of this species. Much to my surprise I find them to be distinct from the 

 forms {Lingulella hella and L. hellula, PL XIX) I collected on Little Belle Island and Great Belle 

 Island, Conception Bay, and those (Lingulella grandis (Matthew), PI. XXXVIII) tentatively 

 compared with the species by Matthew. The shell is more elongate and convex than that of 

 Lingulella iella (Walcott). Two specimens of the ventral valve are illustrated (PL XXIX, 

 figs. 3 and 3a). No dorsal valves occur in the material available for study. 



The outer surface is exfoliated from all of the specimens so as to show the shiny surface 

 of the inner layer described by Whiteaves [1878, p. 226]. One of the broken ventral valves 

 shows a narrow pedicle groove. 



The specific name was given in honor of Mr. E. Billings. 



Formation and locality. — ^tipper Cambrian; (314a [Whiteaves, 1878, p. 226]) Shales on Kelleys Island, Concep- 

 tion Bay, Newfoundland. 



, Lingulella bobnemanni (Walcott). 



Plate XXX, figures 18, 18a-c. 



Lingula attenuata Boknemann [not Sowerby], 1891, Nova Acta Acad. Cses. Leop. -Carol. Germanicse Naturae Curio- 

 sorum, Bd. 56, No. 3, pp. 437-438, PI. XIX (XXXIV), figs. 1-10. (Described and discussed in German, see 

 below for liberal translation. Figs. 10a, 4, 8, and 7 are reproduced in this monograph, PI. XXX, figs. 18, 

 18a-c, respectively.) 



Obolus (Lingulella) bornemanni Walcott, 1901, Proc. U. S. Nat. Mus., vol. 22, pp. 687-688. (Described and dis- 

 cussed essentially as below as a new species.) 



The original description by Bornemann follows : 



Shell oblong oval, sharply pointed toward the beak, marked with fine concentric stripes which are usually regular, 

 and also often marked with large, irregular, concentric folds. Faint radiaj or longitudinal striation usually appears 

 distinctly on the surface in the center of the shell. At the vertex there is usually a distinct, straight, longitudinal 

 impression. 



Shape exceedingly variable, often unsymmetric, short rounded-triangular or almost circular, or narrower and 

 elongated, more or less arched or even flat. The long-extended specimens resemble Lingulella (Lingulepis) acuminata 

 (Conrad); others agree perfectly with Murchison's original figures of Lingula attenuata; others again may be compared 

 with Lingulella davisi (McCoy) and were at first placed with that species. The simultaneous occurrence in enormous 

 multitudes and the numerous transition stages leave no doubt that all these forms belong to one species, and the average 

 type of them fits best to Lingula attenuata Sowerby. 



Size, 2 to 9 mm. 



The state of preservation is best in the slates, yet there the specimens are mostly pressed flat. The specimens 

 existing in great numbers in the sandstones often still exhibit their original arching, but the delicate shells are 

 ordinarily distorted in an irregular manner and poorly preserved. 



Bornemann [1891, p. 437] identified this species with Lingula attenuata Sowerby, on account 

 of the resemblance in outline of many of the specimens. Other specimens closely resemble Linr- 

 gulella (Lingulepis) acuminata (Conrad) from the Middle and Upper Cambrian of North America. 

 It is so improbable that a species of this character should persist from Middle Cambrian time 

 to Middle Ordovician time that, notwithstanding the resemblance, I think it is better to 



