10 TETRERES MURATA. 



membrane. This feature is common in the Terebellids and others. Meyer, like Cunning- 

 ham and Ramage, again suggests that the peristomial lobes may represent the dorsal 

 division of the foot of the first segment, and Allen says that in Poeciloch&tus the feet of 

 the first segment are much enlarged and directed forward. Meyer further thinks that 

 the Hermellidae are closely related to the Spionidae. 



The body behind the foregoing is divided into three regions, viz. the first, devoid of 

 hooks, and with four bristled segments, the second of about forty segments (Allen) with 

 bristles, hooks and gills, and lastly, the caudal tube with its crenate and frilled extremity. 

 The dorsal surface anteriorly is somewhat flattened, or at first grooved, then rounded 

 posteriorly, whilst ventrally it is rounded in the first region and grooved in the second. 

 The first region is firm and rounded, then a slight dilatation occurs at the commencement 

 of the second, and little tapering ensues till near the tail, where, after gently diminishing, 

 it tapers somewhat abruptly to the caudal tube. The general colour of the body is buff, 

 with dark chocolate-brown markings in the region of the thorax and peristomium. The 

 branchiae are dark olive-green, and the smooth caudal portion is also dark green (Allen). 

 The first segment presents dorsally a pair of branchiae somewhat less than the second, 

 then a free lamella divided into two, viz., a truncated flap with a conical median papilla, 

 followed by another with two papillae, broadly conical, then the setigerous papilla, and 

 lastly the ventral cirrus, which is conical on one side and bifid on the other. The 

 bristles differ from the succeeding in being longer, simple, finely tapered and smooth 

 (Plate CXXIII, fig. 1 c). They therefore correspond in structure with the enclosed 

 bristles observed in Sabellaria spinulosa, and are usually, in the preparations, directed 

 forward and inward toward the mouth. 



The other bristles of the region, viz. on segments 2 — 5, consist of flattened spatulate 

 forms with translucent tips — split like a brush and directed dorsally forward and slightly 

 inward. Each (Plate CXXIII, figs. 1 d and 1 d 1 ) has a fillet or rim at the base, then the 

 striated shaft slightly dilates all the way upward to the flattened faintly striated blade, 

 which has a brush-like tip. When these bristles pierce the surface, the tip is pointed and 

 entire, but it subsequently becomes frayed. In each tuft between these are slender 

 tapering bristles (Plate CXXIII, fig. 1 e) with hair-like tips which are minutely spiked so 

 that foreign structures readily adhere. These are shorter than the spatulate forms. The 

 dorsal bristles of this region are powerful organs borne by four large flattened lamellae, 

 which increase from the first to the last, and have a direction obliquely outward and 

 backward. Their structure is uniform throughout, each tuft having large flattened 

 spatulate bristles arising from a bristle-sac or cell, the striated shaft dilating gently from 

 the base to the oar-like tip where a more decided enlargement occurs, and then slightly 

 narrowing distally. 



The next region of the body is characterised by the great development of the 

 branchiae, and by the presence of the forty lateral lamellae for the hooks. A typical 

 foot consists of the branchial process dorsally, the thick lamellae with the hooks on the free 

 ridge, which has a rounded end dorsally, but ventrally the obliquity of the edge leaves a 

 bluntly conical process followed by an acutely conical cirrus or flap behind the ventral 

 bristles, and lastly, the edge of the latter is connected with the body by a free frill with a 

 notch in its margin. Such is the condition in one of the large feet in front, but by-and-by 



