668 MR J. T. CUNNINGHAM AND MR G. A. RAMAGE ON THE 



fascicles of capillary setae in 18 somites, commencing with the somite behind the 

 buccal. These setae are almost straight, with a very long attenuated extremity, 

 winged. From the 6th setigerous somite to the 18th the neuropodial element 

 is an uncinigerous torus, bearing uncini in a single series : these uncini have a 

 long handle or manubrium inserted in a socket in the torus. Behind the 18th 

 somite the notopodial element is wanting; the neuropodial is a flat pinnula 

 provided with uncini of the typical kind, i.e., pectiniform and short, with three 

 or four teeth (vide PI. XLIV. fig. 29). 



Anatomy. — There is but one pair of nephridia, situated in the first chsetiferous 

 somite. 



Larva belonging to the Terebellidce. 



In fig. 30 is shown the appearance under the microscope of a pelagic larva 

 obtained by the tow-net near shore at Granton, and believed by us to belong 

 to some species of the family Terebellidae. This larva was contained in a trans- 

 parent tube, evidently secreted by itself; it is not an uncommon thing for the 

 larvae of tubicolous forms, even when leading a pelagic existence, to be provided 

 with tubes. The intestine in this particular specimen is slightly convoluted, a 

 point in which the larva differs from any adult Terebellid. Larval tentacles 

 are growing from the prostomium, and there are a pair of otocysts behind the 

 anterior end, probably closely connected with the oesophageal nerve com- 

 missures. Anteriorly the somites are provided with fascicles of acicular chaetae ; 

 but on the posterior half there are curious thin knobbed processes, a larval 

 form of parapodia, which we have not further investigated. The whole larva 

 was very transparent. 



Fam. Sabellidj;=Sabellacea, Malmgren. 



The Sabellidae were separated from the Serpulidae by Malmgren : the 

 distinguishing characters are as follows : — Body almost cylindrical, or but 

 slightly depressed, straight, pointed at the posterior end, consisting of two parts 

 — an interior of few (5 to 12) somites, in which the tori uncinigeri are ventral, 

 and the fascicles of capillary chaetae dorsal, and the rest of the body in which 

 the tori uncinigeri are dorsal and the fascicles of capillary chaetae ventral. In 

 the posterior part there is a ventral longitudinal sulcus, sometimes continued 

 on to the dorsum of the anterior part. The first segment has a collar. The 

 branchiae are long straight filaments, in two groups, those of each coadnate 

 at the base ; each filament being provided interiorly with a double series of 

 short thin processes ; exteriorly the branchial filaments are usually naked, but 

 sometimes provided with eye-spots, or short spatulate processes. Tube of 

 the animal straight, cylindrical, membranous, usually coated with black mud, 

 sometimes with grains of sand or other particles. 



