80 



of the lower valve, particularly the ventral margin, generally 

 flattened and smooth. In its young state this shell is quite 

 regular, but becomes increasingly irregular with age. 



Great Britain. 



2. H. Giganteus (pi. xx. f. 3. 4. 5.) Hinnita gigantea, 

 Gray in Ann. of Philos. Aug. 1826. Lima gigantea. Id. in 

 loc. cit. 



"T. oblonga, extus pallide brunnea confertim radiato-sul- 

 cata, extus alba, margine cardinali purpurea ; Long. 4. ; alt. 

 5. poll." 



" Irregularly oval, thick, radiately striated, with the ears 

 small, narrow, hinge thick ; colour pale brown, with reddish 

 radiating streaks, inside white, hinge purple." 



3. H. CORALLINUS. 



" T. valde irregulari, extus corallino-rubra, valva superiore 

 radiatim costella, costellis muricato-subasperis : intus pallide 

 sub-fusca, marginibus basalibus sordide purpureis ; long, et 

 alt. subaequalibus." 



" Shell very irregular, outside of a fine coral red, upper 

 valve with small radiating ribs, here and there muricated ; 

 inside pale subfuscous, basal margins dull purple ; muscular 

 impression having the appearance of a horny substance 

 veined with the same as the other parts of the inside, its 

 lower edges variegated with pale dull purple ; inside composed 

 of a distinctly facetted crystalline substance, with occasional 

 black coriaceous spots near the edges Lower valve paler in 

 colour than the upper ; very rough with the irregularities of 

 the sand-stone rock upon which it has been placed." 



Eastern Africa. 



I am unable to give a figure of this shell, as the only known 

 specimen was in the collection of the Rev. D. Goodall, 

 which has been distributed in various quarters since the 

 lamented death of that dignitary. 



