Qibbula.] 



GASTROPODA. 



135 



Subfam. 2. GIBBULIN^E. 



Frontal lobes and jaws present. Lateral teeth of radula fre- 

 quently exceeding 5 on each. side. Shell pearly ; peristome incom- 

 plete. 



KEY TO GENERA. 



A. Shell auriform, spire short, aperture oval, wide . . . . FOSSARINA. 



B. Shell conical. 



a. Shell small, perforate or imperf orate, whorls often gibbous 



near the suture, smooth or spirally ribbed . . GIBBULA. 



aa. Shell rather large, imperforate, with moniliforra spiral 



ribs . . . . . . . . . . . . CALLIOSTOMA. 



C. Shell depressed conical, form of Solarium. 



ft. Umbilicus partly filled by a prominent spiral funicle or 



rib . . . . . . . . . . . . MONILEA. 



aa. Umbilicus wide, without internal funicle . . . . MINOLIA. 



D. Shell globose-turbinate, small, whorls granose-lirate ; outer 



lip crenulate ; columella with a tooth or notch at base . . EUCHELUS. 



Genus 1. GIBBULA, Risso, 1826. 



Gibbula, Risso, Hist. Nat. Europe Merid., iv, 134. Type : G. magus, L. 

 Gibbula, Risso, Man. Conch. (1), xi, 12, 195. Phorcus, Risso, i.e., 133. 

 Forskulia, H. & A. Ad., G.R.M., i, 432. Magulus, Glomulus, Puteolus, 

 Phorculus, Tumulus, Gibbulastra, Colliculus, Monterosato, Bull. Soc Mai. 

 Ital., 1888, 169-177. Steromphala, Gray, P.Z.S., 1847, 146. Korenia, 

 Friele. Eiirytrochus, Fischer, Icon. Coq. Viv., Trochus, 1880, 417. 

 Calliotrochus, Fischer, I.e., 418. 



Animal having the tentacles long, annulate, ciliiform ; epipodial 

 line with 3 pairs of cirri ; frontal lobes large, fringed ; the ocular 

 peduncles rather short. The radula has the formula oo 1. 5 + 1 + 5. loo; 

 the central tooth rhomboidal, constricted above ; the outer lateral 

 irregular in form. 



Shell usually perforate or umbilicate, conical, the spire moderately 

 elevated ; whorls often gibbous or tuberculose beneath the sutures, 

 smooth or spirally ribbed ; the last generally angular at the periphery ; 

 aperture subrhomboidal ; columella oblique, dentate or subsinuous 

 at base ; outer lip acute. 



The species of Gibbula are very numerous, and are nearly all littoral 

 or laminarian in station. The group is distributed through all seas, 

 except upon the coasts of America, which have not a single species. 



KEY TO SPECIES. 

 A. Shell umbilicated. 



a. Smooth or delicately spirally lirate ; pink or purplish, with 

 white blotches and zigzag streaks below the suture and 

 around the periphery . . . . . . . . fulminate. 



aa. Distinctly spirally lirate. 



b. Spiral lirse fine, numerous, about 18 on the penultimate 



whorl . . . . . . . . . . tasmanica. 



bb. Spiral lirae coarse, 7 to 8 on the penultimate whorl . . scamnata. 



