HYALINIA HELVETICA. 49 
The LINGUAL RIBBON is usually about three mill. long, and composed of about 
forty arcuately transverse rows of teeth; the small median teeth are as usual 
tricuspid, but the central cusp is at times only feebly developed, resembling in 
this respect the true H. glabra, with which this species was so long confused; there 
are two undoubted lateral teeth at each side, bearing three irregular cusps or 
cutting points in addition to a transition tooth, in which the endocone is faintly 
developed, but the eetocone has disappeared ; the marginal teeth are all strictly 
aculeate, and vary in number from nine to fourteen or even more on each side. 
Fic. 82.—Transverse row of teeth from the odontophore of Hyalinia helvetica, x 200, showing the 
more usual form of the median tooth. The animal collected by Mr. C. Oldham at Bettws-y-Coed, 
Wales (after a photo, by Mr. W. Moss). 
ely 
Fic. 883.—Transverse row of teeth from the odontophore of H/. helvetica, X 200, showing the truncate 
mesocone of the median tooth. The animal collected at Llieniog Castle, Anglesey, by Mr. T. Rogers, 
and the palate prepared by Mr. J. W. Neville (after a photo. by Mr. W. Moss). 
The formula of an Anglesey specimen is 
0 Le 2 1 2 0 —_ 2 
Io + og tat Se +42 x 40 = 1,080. 
Food and Habits.—/Hyalinia helvetica inhabits by preference very 
shady and almost gloomy woods and thickets. In the original locality 
at Marple, where this species is found plentifully beneath stones, among 
Fic. 84.—Wood at Marple, Cheshire, Mr. C. Oldham collecting //yadinia helvetica at t 
spot where Mr. Thos. Rogers first found the species. (Photograph by Mr. T. Baddeley). 
nettles, garlic, dog’s mercury, ete., the hanging woods are so dense that 
the sun scarcely ever penetrates within their recesses. It is especially 
11/2/07 D 
