The jMiciio&cope. ;)7 



also terminate each in a single hook-like continuation larger and 

 more conspicnons than the frontal hooks, (Plate II, fig. 85.) The 

 oral annulus is beaded, and the oral cilia jiroject apparently in a tuft. 

 Immediately behind the oral ring is a deep, narrow, transverse 

 sulcation, rather less than one-half as long as the diameter of that 

 part of the head, the former measuring y-Vo" inch, the latter about 

 -^u". It is difficult to conjecture the function of this peculiar feature. 

 The tactile hairs are very long, and there are several additional 

 vibratile setfe on each side of the oral ring which are noticeably 

 straight and stiff, yet movable. The ventral cilia are in two long 

 lateral bands, the intervening space being smooth and naked. Eye- 

 like papillfe were not observed. 



The back and sides are completely clothed by a coat of mail 

 ■composed of transparent, imbricated, rhombic scales, their free and 

 sharply pointed anterior ends being directed forward. They are not 

 more than xoVtt inch in length, and when examined under high 

 amplification, present a beautiful appearance. An attempt has been 

 made in Plate II, fig. 32, to show this, but with very moderate suc- 

 cess. The lateral margins seem to be thickened, and the posterior 

 border of each scale a2:)pears to bear a minute, supplementary, trian- 

 gular scale. Each of these cuticular appendages is probably shaped 

 as shown in Plate II, tig. 34, its posterior end being truncate, and 

 the arrangement presumably that shown by fig. 33. The thickening 

 of the lateral borders may be due to the slight over-lapping of the 

 transparent scales, but I am at a loss for an explanation as to the 

 cause of the minute but very noticeable triangles.* 



The oesophagus is short, rarely exceeding one- sixth of the length 

 of the entire animal. I have obsei-ved a water- vascular system in 

 this species, but the two ciliated tubules seen were traced for so short 

 a distance and so incompletely investigated, that I can now only 

 record their undoubted presence. 



This interesting creature was quite abundant in the gatherings 

 made while its relatives were being studied, but I have not seen an 

 extruded egg, and have not succeeded in keeping the animal alive 

 long enough in confinement to mature the egg even when an indi- 

 vidual has been found with one forming in the ovaiy. A specimen 

 in the latter condition is not often to be obtained. 



.9. Chcetonotus maximus, Ehr. 

 A form which I have identified with this species is not uncom- 

 mon here. It is described by its discoverer as a large Chaetonotus, 



♦Since this was written an individual has been seen with the margins of the scales 

 somewhat convex. 



