726 Henry B. Ward, 



posterior rosette is a conspicuous, highly developed Compound fold 

 or rüffle. This is borne on the angle of transition between the 

 distinctly flattened ventral surface and the arched dorsum. From 

 the dorsal aspect the ruffles are seen in profile only. As they are 

 reflexed over the ventral surface and cover its lateral portion, one 

 sees almost the entire frill in a purely ventral view of the worm 

 (Fig. 2). The lateral frills or ruffles are thick, heavy, dark, with 

 edges rounded, often slightly thickened, and smooth (Fig. 9). At 

 the same time the margin is notched, crenated, and subdivided into 

 rounded lobes at diiferent points and in different specimens. The 

 color as well as the mass is due to the crowded vitelline follicles 

 which are visible even in alcohol material as dark dots, thickly 

 distributed thru the folds, reaching almost to their margins where 

 the arrangement is open enough to permit them to appear as dis- 

 crete structures. In the deeper portions of the folds they lie so 

 close together as to impart a uniform dark gray tone to the entire 

 area. Wagener (1852) says of the ruffles: "Je grösser das Thier, um 

 so mehr sind diese Krausen entwickelt, die Breite dieses Falten- 

 Eandes mochten an dem grössten gesehenen Exemplare in der Mittel- 

 linie des Thieres ungefähr 4 mm betragen." He pictures the worm 

 in natural size and in relaxed or extended condition, with the folds 

 of the ruffles partly (in his Fig. 2) or almost entirely (Fig. 1) flattened 

 out, and then also the animal in greatly contracted condition (Fig. 3). 

 In the latter figure the folds appear closer, more numerous, more 

 highly convoluted by far and more pronounced as a distinct part 

 of the body than in the other figures. This figure resembles those 

 of later obervers more than his illustrations representing the worm 

 in an extended condition. As a matter of fact these latter illustrations 

 are just those which have been copied widely while the contracted 

 figure which is closely identical with those of later investigators 

 has remained relatively unknown or at least unnoted. Of the corre- 

 sponding condition of the worm Wagener says (p. 544) "das zu- 

 sammengezogene oder auch todte Thier ist voller Querrunzeln, die 

 Seitenkrause stark gefaltet, die Schwanzkrause an den Körper 

 herangezogen, so dass die beiden Oeffnungen des Trichters kaum zu 

 finden sind. In diesem Zustande liegt der grösste Theil der Seiten- 

 krausen auf der fast platten Bauchseite, während an den Rändern 

 der gewölbten Rückenseite nur wenig von den Falten zu sehen ist." 

 Now this description corresponds exactly to that given by other 

 investigators so that one is forced to conclude that the elongated, 



