Page:Beautiful·Shells·of·New·Zealand-Moss-1908.pdf/36

 the same colour as the shell. The shells are very light and fragile. A singular provision for its eggs is found attached to the female Janthina, in the shape of a float, or raft, to the under surface of which the eggs in little bags or capsules are attached, and there they remain until hatched.

JANTHINA EXIGUA (Plate VII.).—Fig. 1 is the smallest of the Janthina found in New Zealand, being rarely half an inch in width. The whorls are more rounded than in the other two varieties, and the spire is usually the same violet colour as the mouth, and the grooves on the shell are deep and prominent.

JANTHINA FRAGILIS (Plate VII.).—Fig. 2 is sometimes over an inch in width, the spire being much lighter in colour than the rest of the shell, frequently indeed being white. The grooves on the shell are fine, but clearly visible.

There is another variety occasionally found in New Zealand, the Janthina globosa, like the Janthina exigna in shape, but larger, and the grooving being very faint the shell has a glistening appearance. This variety is rare.

CANTHARIDUS IRIS (Plate VII.).—Fig. 3, from Iris, a rainbow, well describes the colour of this pretty little shell, seldom more than one and a-half inches in length. Pink, purple, yellow, and red seem to be the prevailing colours; and they are arranged in irregular waving lines on its smooth and polished surface. The interior is highly iridescent. It lives amongst seaweed and rocks below low water mark. The Maori name is Mata-ngo-ngore, which is also used for the Calliostoma shells on Plate VI.

'''CANTHARIDUS TENEBROSUS, var. Huttoni''' (Plate VII.).—Fig. 7 is a little bluish-black shell, about a-third of an inch long, with fine striæ or grooves running down the whorls. Alive, it is found in great numbers at low water on marine grass banks in harbours, and seems to be very active, as the anchors and cables of boats, moored for a few hours over one of their favourite haunts, will be liberally sprinkled with them.

CANTHARIDUS PURPURATUS (Plate VII.)—Fig. 8 is a heavier and rougher shell than the Iris, and of a rose-pink colour. Sometimes the whole shell is of this colour, but frequently only the top of the spire. It also lives amongst seaweed and rocks; but when living on grassy banks in harbours seems to lose its pink colour and become a pale grey.