APPENDIX. 271 



orange yellow hue of the dead mollusk may be perceived near 

 the apex. The spiral strife are very decided, and beneath the 

 microscope often seem to be punctated. The base or anterior 

 disk is much rounded, and the sudden perforation is not broad- 

 mouthed. The aperture nearly occupies one half of the ventral 

 area ; the body-lip is free except at the posterior extremity, 

 near which it curls back a little. 



Mr. Clark has noticed the animal. The cilia of its tentacles 

 and cirrhi are less close-set than in Skenea ? divisa, the curved 

 auricles of the foot flatter and broader ; the foot more rounded 

 at both extremities, and the bulgings for the eyes were pro- 

 minent. The animal is very active. 



Troclms pusillus, according to Mr. Clark, has a very similar 

 animal. 



VoL iii. p. 1G7, Skenea? costulata. 



In consequence of the specimen having been lost, it could not 

 be engraved on the plate referred to in our text. We are in- 

 debted to our kind friend Mr. Alder for an original drawing, 

 (Plate CXXXII. f. 1, 2, 3,) taken from the same shell. 



Vol. iii. p. 174. Note to Turritella communis. 



A second species of Turritella is mentioned in Brown's " Illus- 

 trations" (p. 9, pi. 8, f. 57, 5S), as found at Tenby by Mr. 

 Lyons. We cannot recognize it, but copy the description : — 

 T. minor. " Shell acute ; with fifteen well defined, rounded, some- 

 what short volutions, tapering to a sharp point, covered with very 

 fine, regular, spiral striae ; aperture subrotund ; outer lip thin. 

 Length three-eighths of an inch, breadth not an inch." 



The figure reminds one a little of the genus Mesalia. Can 

 it be meant for Aclis ascaris ? In the stated breadth there is 

 clearly an omission, and judging from the proportions of the 

 figure it should be " not the seventh of an inch." 



Vol. iii. p. 192. Cerithium reticulatum. 

 Add to the synonyms, — C. reticulatum var. h. Thompson. 



