﻿IIEMIPIIOLIS CORDIFERA. 139 



brownish flesh-coloi' ; the radial sliields are usually different from the 

 disk, and may be bright or dull green, dark brown, lake-red, bluish, dull 

 brown, or gray ; the arms also commonly differ from the disk, and are 

 commonly banded ; one specimen had them sap-green, another lake-red, 

 and a third brownish flesh-color, banded with black. The disk seems 

 never to be uniform, but always speckled or mottled with two or more 

 colors. The tentacles are red. In other respects this species seems to 

 be singularly uniform. The young, when very small, differ extremely 

 from the adult ; they are found clinging to the arms and disk of the 

 parent. A specimen with a disk of .5""°, had arms 1.3°"°' in length, and 

 with eight joints ; the Avhole upper surface of the disk was occupied by 

 six primary plates, of which the middle one was regularly pentagonal, 

 the other five surrounding it regularly hexagonal ; the upper arm-plates 

 were reduced to a small oval plate at the outer end of each joint, while 

 most of the upper surface was occupied by the side arm-plates, which 

 met along the middle line ; they met also below, but the under arm- 

 plates were longer than the upper, and had the form of a long, sharp 

 wedge, with the outer side a little curved ; the arm ended in a three- 

 lobed papilla, evidently the beginning of a new joint ; the arm-spines 

 were only two in number, and the lower one had two or three hooks 

 along its edge ; the mouth occupied more of the under surface than in 

 the adult ; on each side of the mouth-shields apj^eared a squarish papilla 

 (side mouth-shields) ; the jaw, with its three teeth, was prominent, and 

 outside of it were the two mouth-papillae, already well formed. Another 

 young one, with a disk of 1™-, showed already great advancement ; the 

 arms were 7.3""°" long, and had twenty-two joints ; the upper arm-plates 

 were large and heart-shaped, with the point inward, resembling much 

 the adult shape of AmpMura tenera ; the imder arm-plates were long, 

 with straight outer and lateral sides, and an angle within; the side 

 arm-plates had become much more restricted ; there were three arm- 

 spines, rather blunter than those of the adult ; only at the tip of the 

 arm did the lowest spine have hooks ; the mouth-parts were nearly as 

 in the grown animal, but with wider mouth-shields ; the whole centre 

 of the upper disk surface was still occupied by six primary plates, but, 

 in addition, there was a radiating row of three primary plates in each 

 interbrachial space, and in each brachial space a single additional plate, 

 between which and the base of the arms were the beginnings of two 

 radial shields ; all these plates were connected, and made an elegant 

 mosaic ; in the grown animal they may be recognized by their greater 

 size, but they are then quite separated by numerous smaller scales. A 

 specimen with a disk of 2.3""°' had the primary plates a good deal 

 rounded ; the radial shields were fully formed, and a few of the smaller 

 scales had begun to appear. 



This species " is gregarious, living in companies of twenty or thirty. 



