232 MYRIANIDA PINNIGERA. 



and 15. The proboscis is 4 mm. long, and has fifty to sixty pointed papillas at the edge. 

 There are no lateral ponches or stomach. Little difference exists between this and the 

 foregoing species. 



Malaquin a considers from his observations on three examples that the budding 

 occurs after the sixty-sixth segment of the nurse-stock. The segment concerned is the 

 penultimate one, and he terms it " Zoonite formateur" The pygidium of the nurse-stock, 

 therefore, he found at the extremity of the twenty-ninth bud. With this segment 

 {zoonite formateur) the new buds are connected. On the other hand, he has observed 

 zoonites formateur s at a distance from the pygidium and independent of it. This author 

 has studied the growth of the buds, the early segments of which present no appendages ; 

 then minute processes appear in the succeeding segments, in the first or youngest bud on 

 the pygidium (Malaquin). In the next series of segments forming a bud, these appen- 

 dages are better developed, and so until in the third bud {e. g.) bristles occur, and the 

 alimentary canal of the nurse-stock goes through each to the terminal bud. Each stolon 

 possesses a zoonite formateur in front of the pygidium, the former having no appendages, 

 the latter having them. Malaquin thinks the formative segment in the buds gives rise to 

 additional segments in front. The anterior segment, on the other hand, is thickened 

 dorsally and gives rise to head and post-cephalic segment. The author minutely describes 

 each successive bud, and the appearance of the various appendages in it, including the 

 eyes for dorsal and ventral vision, and the swimming-bristles. The terminal stolons — 

 male or female — thus developed show great activity, and by-and-by break from the 

 nurse-stock and swim freely away. The male bud (Polybostrichus) had thirty segments 

 besides head, peristomium, pygidium, and the formative ring in front of it. Their 

 sexual elements were ripe. The first four segments have no swimming-bristles, and 

 contain the genital glands (four pairs). They have spots of brilliant orange-red 

 pigment. The head bears dorsally a long median and two shorter lateral tentacles, and 

 beneath are the split palpi, or, as he terms them, the anterior lateral antenna and the 

 palpus. The peristomial segment has a long dorsal and a shorter ventral tentacular 

 cirrus. 



The female bud (Sacconereis) has about thirty-five segments, and twenty-three bear 

 swimming-bristles. The head carries a median and two lateral foliate tentacles. The 

 post-cephalic (peristomial) has a single tentacular cirrus. The eyes are, as in the male, 

 a larger anterior and a smaller posterior. The ovigerous sac occupies the fifteen or 

 sixteen median segments, and has a median constriction. It is proportionally smaller 

 than in Autolytus, and has exactly forty-three large orange eggs (Malaquin). The sac is 

 a transparent secretion of the mucous glands of the ventral division of the foot. The 

 colouration is similar to that of the male. The natatory bristles begin on the first foot, 

 though occasionally they vary. These stolons, ■$ and ? , are devoid of a proboscis and 

 proventriculus. 



• l ' Recherches sur les Syllidians/ pp. 287 — 305. 



