362 EVARNE HUBRECHTI. 



is somewhat bluntly rounded. The remarkable feature about it. however, is the presence 

 of a broad web or lamina attached to its lower surface, and which tapers from base to 

 tip. The organ, therefore, forms an efficient rudder. The body is delicate and brittle, 

 and the length of the bristles still further adds to the characteristic appearance. 



Scales (Plate XXXIII, fig. 1), fifteen pairs, thin but tough, entirely covering the 

 back, comparatively large and apparently smooth to the naked eye, but minutely granular 

 under a lens. The first pair are rounded, the succeeding more or less ovate, and all with 

 a smooth border. The entire surface is studded with minute horny spines, which increase 

 in size from the inner to the outer border, and especially posteriorly. No part of the 

 scale is free from them. It sometimes happens that a few of the larger conical spines 

 project beyond the posterior border under examination, but otherwise the edge is smooth. 

 In shape almost all the spines are acutely conical. The scales are pale, and the scar for 

 the pedicle has an unusually large area behind it, from the great development of the 

 posterior region. The scales, as a rule, adhere firmly. In a mounted scale a number of 

 rounded bodies of various sizes, with a distinct capsule and granular contents, occurred, 

 along with certain rectangular bodies composed of two halves, like Desmids. Their 

 nature is enigmatical. 



Feet. — The first bears a short, slightly curved bristle or two of the dorsal pattern, 

 and resembling the shorter forms next the body in the typical foot. 



The second foot presents a double ellipse — one for each division — with the project- 

 ing papilla for the spine, the inferior having in addition a fleshy digit-like process 

 above the spine. A few of the inner bristles of the dorsal tuft are short and curved like 

 those of the tentacular cirrus, each, however, having a smoothly pointed tip. The chief 

 bristles are long, translucent, and tapering, with a long bare tip marked by wide and 

 slightly oblique spinous rows, so that in some views it resembles an Equisetum of glass. 

 The ventral bristles are slender and elongate, with long spinous regions tapering to a 

 delicate tip, which is bare, and provided with a terminal hook. The filiform tip of the 

 long ventral cirrus extends beyond the bristles. 



The next foot leads to the typical shape, which is peculiar, since in a ventral view 

 the tip is rounded. In profile, again (Plate XXX, fig. 10), the outline of the ventral 

 division is comparatively deep and rounded, with the spine near the middle, and the bristles 

 project as a broad fan. Dorsally the bristles (Plate XL, fig. 1) are remarkable for their great 

 length, diaphanous nature, and brittleness — conditions pointing to a pelagic habit. The 

 dorsal lobe itself forms only a small boss or eminence, and is thus in marked contrast 

 with the same region in Uvarne impar. From the inner side of this eminence spring 

 a few short, slightly curved tapering bristles, with closer rows of spikes, next which 

 are some shorter straight ones (Plate XL, fig. 3). The rest are large straight bristles 

 (Plate XL, fig. 2), tapering almost from the base to the smooth and sharp tip. The 

 spinous rows are short, slightly oblique, and very wide, as in an Bquisetum, the appearance 

 of the whole being diagnostic. The ventral series consist of elongated and slender 

 bristles (Plate XL, fig. 4), with long and finely tapered spinous regions superiorly. They 

 terminate in a long smooth tip, which is bifid and slightly hooked. The bifid condition, 

 however, is difficult to detect in some, and interiorly the tips are simple. The bristles 

 can be followed in the diaphanous foot inwards to the muscular boss at the spine. 



