Vol. 55.] ECTOMARIA AND HORMOTOMA. 265 



therefore I was not quite satisfied with the correctness of the identi- 

 fication. Through the kindness of Prof. Lindstrom, however, I have 

 been able to compare the British with Swedish specimens. He lent 

 me examples from three different localities in Gotland, namely, 

 Gothem, Botvaldavik, and Horsne, which resemble the British shells, 

 more especially the example from Gothem, which appears to have a 

 slightly smaller spiral angle than those from the other places. 

 Hisinger's original, Prof. Lindstrom states, was ' found by him in a 

 detached stone near the church of Gothem. The rock is a variety of 

 oolite peculiar to a quarry at the base of Barabacke, and consequently 

 there cannot be any doubt of its being derived from that place.' ^ In 

 his letter, when sending me the examples, he writes, ' There may be 

 slight variations as to the dimensions of the whorls, but on comparing 

 them with Hisinger's type I am convinced that thej' are of the same 

 species.' Thus 1 have no hesitation in referring the British shell to 

 this species. The first notice of its occurrence in England is that 

 of Salter,^ who mistook it for Terehra(?) sinuosa, Sow., not having 

 observed its identity with Hisinger's species. T. (?) smuosa, Sow., 

 however, is a much smaller shell and its structure is quite distinct, 

 there being no sinual band, and the lines of growth are sigmoidal 

 as characteristic of Loxonema. M'Coy was the first to refer an 

 example of this form as well as Salter's specimen to MurcJiisonia 

 cingulata (His.).^ But he is at fault in considering an Irish shell 

 as a variety of this species,^ for it has narrower whorls and the 

 sinual band is situated higher up. 



Ke semblances. — This species differs from the other members of 

 the genus Hormotoma in having less convex whorls, the band situated 

 lower down on the whorl, a subangularity on the base, and in having 

 the surface covered with fine spiral striae which are reticulated by 

 the lines of growth. These spiral striae are visible only on well- 

 preserved examples, and the surface of but one of those sent 

 from Sweden (that from Botvaldavik) is good enough to show 

 traces of them. This shell also shows the lines of growth on the 

 sinual band, which I have not observed so clearly on any British 

 specimen. In spite of the differences in structure from the type, 

 I consider it advisable to place this species in the genus Hormotoma 

 for the present, especially as I know of no other genus with which 

 it more nearly agrees. In contour it resembles members of Coelo- 

 caulus, (Ehl., but there the sinus in the outer lip is shallower, the 

 lines of growth do not sweep backward and forward so obliquely, 

 and the umbilicus is deeper. The British species to which it beais 

 most likeness is Hormotoma Pijjeri, but it is distinguished by its 

 smaller spiral angle, less convex whorls, and shallower sutures. It 

 also resembles H. antiqua in the low position of the band and 

 slightly convex whorls, but in that shell the whorls are lower and 

 the lines of growth more oblique. Among American species it is 



1 'Silur. Gastr. & Pter. of Gotland,' Kongl. Svensk. Yet.-Akad. Handl. 

 vol. xix (1884) No. 6, p. 128. 



2 Mem. Geol. Surv. vol. ii, pt. i (1848) p. 357, 



3 ' Brit. Pal. Foss.' 1855, p. 293. 



* ' Syn. Silur. Foss. Irel.' 1846, p. 16. 



