ClDARIS. 
RADIATA. ANOCYSTI. 
477 
the sockets of the teeth. According to this author, the water enters 
the perforated suckers, passes along the five tubes, and escapes at the 
mouth. Future observation, however, will probably assign an oppo- 
site direction to the current, and the perforated tubes on the oral disc 
as the orifices at which the water enters. The organs of reproduction 
appear to be limited to five ovaria, intimately connected, and opening 
by five oviducts, in the perforations of the five plates of the pelvis. 
When in season, the roe fills a great part of the cavity of the shell. It 
is eaten when boiled, and has a flavour not unlike a lobster. 
Gen. I. CIDARIS. — Tubercles and spines connected by a 
central ligament. The avenues of pores are parallel and 
closely placed, rendering the smaller compartments narrow, 
tortuous, and fit only for supporting small spines. The 
plates of the larger compartments have an elevated tuber- 
cle in the middle, with a groove round the base, surround- 
ed with a broad smooth space, which is inclosed on the 
margin of the plate, with a border of small tubercles, des- 
titute of a pit in the summit. On each central tubercle 
there is placed a large spine, connected by the central li- 
gament and investing integument. M. Lamarck (Hist. 
Vert. iii. 53.) considers this central ligament as a muscle 
issuing from the interior, for moving the spine. But it has 
no communication with the interior of the shell. He like- 
wise supposes that the tubular suckers can be withdrawn 
into the shell by the animal. But the division of the canal 
at the base, for the passage of each branch through a dif- 
ferent pore, renders this impossible. Bound the base of 
these large spines, smaller ones are placed, on the ring of 
tubercles, which surround them like a sheath. Each avenue 
consists only of a double row of pores, in pairs, correspond- 
ing; with a single row of tubular suckers. 
o o 
1. C. paplllata . — Primary spines nearly cylindrical, with nu- 
merous rough longitudinal ridges. 
C. p. major, Leske apud Klein^ Ech. p. 125. tab. vii. A. and xxxix.— • 
2. Echinus Cidaris ? var. a. Sower. Br. Mus. tab. xliv.— -Found in deep 
water, Zetland, where it is called the Piper. 
The body of the shell is about two inches in diameter, and depressed at 
both ends. The longest primary spines are about four inches in length. The 
shortest near the mouth do not exceed half an inch. These last are spatu- 
late as well as the small ones on the oral plate. The plates of the division be- 
