SCULPTURE OF WHORLS IN UNIVALVES. 
27 
according to the specie.s, showing great diversity in sculpture, colour- 
ing, and in the spinous, bristly or other appendages thereof. The 
various characters of the whorls may be designated as 
Striate, when the parallel scidpture is fine and close; termed 
Spirally Striate when the stronger lines revolve with the 
whorls, as \n Planoi'his albus (L.); and Transversely Striate 
when they cross the wlioids and are more or less coincident 
with the incremental lines of growth, as in the generality of 
the testaceous mollusca. Tryon and other authors term the 
spiral striation transverse or revolving, and regard the transverse 
strise as longitudinal in character. 
Fig. 40. — A Transversely 
and Strongly-Striate Univalve. 
Ifeli-v caf>crata Mont., 
Perth, 
Collected by Mr. Henry Coates. 
Fig. 41. — A Spirally Striate Univalve. 
Planorbis allms (L.) X 3, 
Scout Dam, Penistone, 
Collected by Mr. L. E. Adams, R.A. 
Hispid, or Pilose, when the whorls are more or 
less densely covered with hairs, as in Helix 
(jranulataKXAQx, H.kiitpiddl^lyxW., etc.; orthe 
hirsute appendages may be of a more downy 
character, as in the young of P. corneas (L.), 
etc., which are then termed Pubescent. 
Fig. 42. — Example: Helix gratmlaia Alder x 2, Ashley Downs, near Bristol, collected 
by Miss F. M. Hele. 
Coronate, when the spinous processes spirally 
encircle the whorls in a coronate form, as in 
Helix aculeata L. 
Fjg. 43. — E.xample : Helix aculeata L. X 8, Bassenthwaite, Cumberland, collected by 
Capt. W. J. Farrer. 
Muricate, Echin.vte, or Spinose,' when the 
granulations or ribs upon the whorls are 
produced to a sharp point, as in Planorbis 
nautileus var. crista (L.). 
Fig, 44. — Example: Planorbis nautileus var. crista (L.)x8, pond, Roundhay, near Leeds. 
Plicate, or Costate, when the whorls are strongly 
ribbed or ridged transversely, as in Helix 
palchella var. costata IMiill. 
Fig. 45. — F^xample : Helix pulchclla var. costata Muller x 8, Pleshey Mount, near 
Chelmsford, collected by Mr. R. Miller Christy, F.L.S. 
