566 MISS JANE DONALD ON THE GENEEA [Nov. I906, 



of about six whorls. Whorls increasing somewhat rapidly, more or 

 less convex. Band prominent, situated considerably above the 

 middle of the body-whorl, and near the middle of the penultimate 

 whorl, of moderate width, bounded on each side by a raised thread, 

 with a stronger thread which is submedian, being placed either in 

 the middle or else nearer the upper thread. Ornamentation above 

 the band, consisting of a strong, rounded keel about midway 

 between it and the suture and a swelling immediately below the 

 suture : consisting below the band on the body- whorl of six or more 

 strong rounded keels, the uppermost being the strongest, and from 

 one to three showing on the higher whorls above the suture. Lines 

 of growth distinct, sharply defined, fine threads curving back to the 

 band above, coming forward immediately below the band and then 

 curving slightly backward, forming strong raised crescents on the 

 band, indicating a sinus of moderate depth in the outer lip. 

 Aperture sub-circular, the inner lip slightly reflected, either 

 adpressed on the body-whorl or free. Base convex. Umbilicus 

 closed. 



Remarks and Resemblances. — The first to record this 

 species is Salter in 1873, but he does not describe or figure it. 

 In 1879 Prof. Sollas describes and figures It under the name of 

 MurcJiisonia corpulenta ; he has but one example, which is poorly 

 preserved, and he does not refer to Salter's previously-named 

 specimens. Mr. P. R. Cowper Reed in 1901 describes and figures 

 Salter's species as Pleurotomaria cyclonema, but does not identify it 

 with that of Prof. Sollas. Through the kindness of Prof. Hughes 

 and also of the Committee of the Bristol Museum in lending me 

 the specimens, I have been enabled to compare them, and I am 

 convinced of their identity. As Salter's name is the oldest, and the 

 species is founded by him on a good representative series of fourteen 

 individuals, and has also since been accurately described and figured 

 by Mr. P. R. C. Reed, it seems best that Salter's name should stand 

 (though he did not give a description or figure) — more especially 

 as the specimen figured by Prof. Sollas is a poor one, unsuitable 

 for a type, and not characteristically represented on the plate. The 

 lines of growth indicate a sinus, and not a slit, in the outer lip. 

 On some examples they are coarse and sub-lamellar, on others they 

 are fine and closely packed, while on others again they vary in 

 strength and nearness on the same individual. Those on the band 

 are either crescentic or subquadrate in form ; they may be similar 

 to those on the rest of the shell, or they may differ in strength and 

 closeness together. The fact of this species having a sinus in the 

 outer lip, together with its other characteristics, necessitates its 

 removal from the genus MurcJiisonia to Lop7iospm, where it must be 

 placed in the Tubulosa subsection of the Bicincta section. 

 It greatly resembles Pleurotomaria laqueata, Lindstrom, 1 which 

 Dr. Ulrich also places in the same group, but it differs in the cha- 

 racter of the band. I have met with twenty-seven specimens of this 



1 ' Silurian Gastropoda & Pfceropoda of Gotland ' Kongl. Svensk. Vet.-Akad. 

 Handl. n. s. vol. xix, no. 6 (1884) p. 102 & pi. ix, figs. 4-6. 



