254 APPENDIX. 



Vol. i. p. 452. AsTARTE SULCATA. 



Plate XXX. f. 5, 6 and CXXXIII. f. 4. 



By copying the erroneous numerals of the writing engraver, 

 we referred figure 5 in the body of our work to A. triangularis. 

 Figure 4 of our supplementary plate represents the sharp narrow 

 ribbed form. Figure 5 of the earlier engraving is intended for 

 the variety with a coloured interior. 



Vol. ii. p. 29. Cardium pygmjeum. 



A small variety has been taken at Unst by Mr. M'Andrew, 

 which has the ribs rather more prominently defined and further 

 apart than in the majority of our English examples. 



Vol. ii. p. 72. MONTACUTA FERRUGINOSA. 



Mr. Alder has communicated to the fifth volume of the Second 

 Series of the " Annals of Natural History," a more complete 

 account of the animal of this shell. Respecting it, among other 

 particulars, he observes that the mantle shows a new modification 

 of that part, intermediate between the plain anterior siphonal 

 fold of Kellia rubra, and the more elaborate form of mantle in 

 Lcpton squamosum. The anterior portion of the mantle is 

 ample, and produced considerably beyond the shell, forming a 

 kind of frill, which becomes gradually smaller and more even as 

 it passes along the base of the shell. Its exterior circumference, 

 lining the shell, is fringed with very delicate filaments, rather 

 short and blunt, which extend completely round the margin of 

 the valves, with the exception of a small space at the umbones. 

 The mantle is open throughout the entire front and base of the 

 shell, but closed posteriorly, and not produced into a siphon. 

 Some interesting notes are recorded on the development of the 

 embryo. 



In the description of shells of the Montacutce given in the 

 text, the terms "posterior" and "anterior," as applied to the 

 extremities, should be reversed, except in the case of Montacuta 

 substriata, where they are correctly employed. 



