SCALPELLUM. 45 



15. SCALPELLUM (?) CRET.E. Tab. I, fig. 11. 



Anatifera cret.e. Steensfrvp. Kroyer's Tidsskrift, 1837 ct 1839, b. ii, pi. v, 

 figs. 1, 2, 3. 



8. valvis lavibiis tenuissimis : scuti umbone prope medium marginis ocdudentis posito ; 

 costis iribus obscuris ab iinibone ad avgulos tergo-Iateralem et hasi-lateralem, et ad medium 

 marginis basalis decurrenfibus : carince ap)ice etmargine basali acutis; disfincii parietes absunf. 



Valves smooth, extremely thin -. scutum Avith the umbo placed nearly m the middle of 

 the occludent margin, with three obscure ridges running from the umbo to the tergo-lateral 

 and baso-lateral angles, and to the middle of the basal margin : carina with the apex and 

 basal margin sharply pointed ; without distinct parietes. 



White Chalk, Denmark, Mus. Univers., Copenhagen. Chalk Detritus, Charing, Kent (?), Mus. Harris. 



Preliminary Memarks. I owe to the kindness of Professor Steenstrup, as in so many 

 former instances, an examination of several specimens of this fossil, which is of interest, as 

 being extremely common and characteristic of the white chalk of Denmark. Amongst 

 the numerous minute specimens from the chalk detritus of Charing in Kent, sent me by 

 Mr. Harris, there are some carinse so similar that I have ventured, with doubt, to rank this 

 as a British species ; the carina, however, in this species, are far from characteristic. I have 

 felt much hesitation in admitting this species in the genus Scalpellum : Professor Steenstrup 

 was originally inclined to believe that the capitulum was formed of only five valves ; 

 could this be proved, the species would very naturally rank with a small recent one from 

 the Island of Madeira, Avhich, owing to the upward growth of the scuta, and to certain 

 pecuharities in the animal's body, I have felt myself compelled to raise to the rank of a 

 genus, under the name of Oxynaspis. But as the valves of S. (?) ereta have never been found 

 united, and as the main ones are very small, fragile, and generally in a broken condition, 

 the small lower ones might easily be overlooked. I have seen, indeed, in two instances, 



the midclle of the basal margin ; the surface between the latter ridge and the occludent margin covered 

 with fine longitudinal elevated lines. 



Scania (Kopinge). Mus. Univers., Copenhagen. 



I have in this one instance departed from my rule of never naming any other valve, except the carina 

 in the genus Scalpellum ; but the scutum here to be described almost certainly belongs to this genus, and 

 is interesting in connection with the homologous valves in 5. tuherculatmn and S. (?) crefce, to which 

 species it is apparently allied, but yet differs greatly from them in the umbo being seated at the upper- 

 most point of the valve. 



Scutum, moderately elongated, slightly convex ; a narrow, prominent, well-defined ridge runs from the 

 apex to the baso-lateral angle, at which point it forms a narrow projection : a second ridge, not quite 

 60 prominent, runs from the apex to the basal margin, to a point rather nearer to the baso-lateral than to 

 the rostral angle. That part of the valve between this second ridge and the occludent margin has four or 

 five faint longitudinal ridges, whereas the rest of the valve is smooth. Internally there is a deep depression 

 for the adductor muscle, above which the surface is simply concave up to the apex. 



