33G CONTRIBUTIONS TO CANADIAN PALEONTOLOGY 



Lake Manitoba; and by Messrs. Tyrrell and Bowling in 1889, on or in 

 Dawson Bay, at Whiteaves Point, at the mouth of Steep Rock River, and 

 at the south end of Rowan Island. 



Some of the specimens from these localities are extremely like the 

 two Lummaton examples of Ij. jiri^icn^n figured by the Rev. G. F. 

 Whidljorne (^op. fit.), but the former are apparently a little the larger. The 

 approximate dimensions of a large and nearly peii'ect specimen from Pen- 

 tamerus Point are : height or length, twenty-eight vam. ; greatest Ijreadth, 

 nine mm. height of outer vulution as measuied in the median line of 

 the doi'sal surface, about nine mm. In some of the speciinens from Lakes 

 Manitoba and Winnipegosis the outer volutiun is more venti'icose than 

 that of the original of the figure on Plate xliv, and not so nai-row at the 

 base. The surface markings are not satisfactorily shown in any of them, 

 but so far as can be ascertained, the shell is practically smooth to the 

 naked eye, though a few obscure and minute lines of growth, parallel to 

 the outer lip and close to it, can be seen with a lens on one specimen. In 

 another, there is a single faint transverse constriction at a short distance 

 from the aperture. 



B. Slightly a))errant and i-eticulate species, whose surface is marked 

 with spii-al revolving raised lines or small ridges, as well as the usual 

 sigmoidal costuke oi' crowded growth lines. 



(S-) LOXONEJIA CINGULATUM. (N. Sp.) 



Plate 44, lig, .S. 



Shell rather large, narrowly elongated and many whorled s]iire 

 between thive and four times as long as the outer \'olutio)i. Volutions 

 nine or ten, the apical ones being imperfectly pi-eser\ed in the few speci- 

 mens collected, compressed conxex and incr<-aslng very slowly in size, 

 those of the spire a little broader than higli : outer volution moderately 

 ooirv(!x, as high as bioad, narrowly roundec] and somewhat produced at 

 the base ; axis imperforate : suture distinrtly deiined : apertui-c subovate, 

 higher than wide and abruptly pointed almve. 



Suiface marked with sniall and very narrow but pronnnent spiral ridges, 

 which are regularly arranged and nearlye(jui(listant,als<i by slightly tiexuous 

 and somewhat sigmoidal lines of growth. In the largest sj)ecimen collected, 

 whciSH surface njarkings are not very well preserved, thoe appear tfi have 

 been about seven spir;d ridges on tin; dorsal surface of the last volution but 

 two, nine on that of the last but one, and probably not less than ten and 

 perhaps as many as eleven or twehe on that of the outer volution. 



