252 MISS JANE DONALD ON THE GENEEA [May 1 899, 



Murchisoniidse. In the meantime, I would place both Hormotoma 

 and Ectomaria provisionally in this family, awaiting the results of 

 further research which may throw more definite light both upon 

 the affinities and limits of these groups. 



I desire here to offer my most sincere thanks to all who have 

 rendered me assistance. For the loan of specimens I am deeply 

 indebted to Mrs. Gray (Edinburgh), the Council of the Geological 

 Society, the Geological Survey of Scotland, Prof. Hughes, Prof. 

 Sollas, Prof. Lindstrom, M. and Mme. (Ehlert, and Mr. Whiteaves ; 

 while Messrs. R. Etheridge, E. T. Newton, R. B. Newton, A. S.Wood- 

 ward, H. A. Allen, Fortey (Ludlow), and Madeley (Dudley), and 

 Herr Rau (Assistant to Prof. Koken) have helped me either by 

 drawing my attention to collections, or by giving me every facility 

 for studying those under their charge. I am greatly obliged to 

 Mr. McHenry for information concerning Irish localities and hori- 

 zons, and to Mr. Goodchild for revising this paper. 



Family Murchisoniidse^ Koken. 



Genus Ectomaeia, Koken. 



Ectomaria, E. Koken, 1896, ' Die Leitfossilien,' p. 395 ; 1897, ' Die Gastrop. des 

 Bait. Untersilurs.' Bull. Acad. Imp. Sci. St. Petersb. ser. 6, vol. vii, no. 2, p. 201. 



Solenospira, E. 0. Ulrich & W. H. Scofield, 1897, Final Rep. Geol. & Xat. Hist. 

 Surv. Minn. vol. iii, pt. ii (Palasont.) p. 959 ; J. F. Whiteaves, 1897, Geol. Surv. Can. 

 ' Pal. Foss.' vol. iii, pt. iii, p. 193. 



MurcMsonia (pars) F. Schmidt, 1858, Archiv Naturk. Liv-, Ehst- u. Kuvlands, 

 ser. 1, vol. ii, p. 202. 



Eunema 7 (pars) J. W. Salter, 1859, Geol. Surv. Can. ' Canad. Organic Rem.' 

 dec. i, p. 30; E. Billings, 1859, Can. Nat. & Geol. vol. iv, p. 360. 



MurcMsonia (pars) E. Billings, 1865, Geol. Surv. Can. ' Pal. Foss.' vol. i, pp. 231 

 &307. 



E^lnema(?) J. J. Bigsby, 1868, ' Thes. Sil.' p. 153; {pars) S. A. Miller, 1889, 

 ' N. Amer. Geol. & Palasont.' p. 403. 



MurcMsonia ? (Eunema ?) R. P. Whitfield, 1882, ' Geol. Wisconsin,' vol. iv, pt. iii 

 (Palseont.) p. 218. 



Description. — Shell elongated, turreted. Whorls numerous, 

 ornamented by spiral keels. The lines of growth slope obliquely 

 backward and then forward, forming a broad but shallow tongue- 

 shaped sinus, situate between two keels near or below the middle 

 of the whorl. Aperture broadly channelled below. 



Dimensions.— The length ranges from about 30 up to 75, or 

 even to 100 mm. if M. Missisquoi, Billings, belong to this genus. 



Remarks. — This genus was first defined by Koken in 'Die 

 Leitfossilien,' p. 395, and was afterwards more fully described by 

 him in ' Die Gastropoden des Baltischen Untersilurs,' p. 201. He 

 gives Murchisonia Nieszkowshii, Schmidt, as the type. I can 

 discern no essential diflPerence between the characters of this genus 

 and those of the genus Solenospira, founded by Ulrich & Scofield 

 for the reception of Eunema (?) pagoda, Salter. I have examined 

 Koken's type-specimens, and have also seen examples which appear 

 to be identical with E. (?) pagoda, Salt., in the British Museum (Nat. 

 Hist.) from Allumette Island. The lines of growth on the latter 



