IS Trof. M'lntosh's Notes from the 



form than S^pio gal/i/i, and tlie aspect diffiMs, The head is 

 characteristicalh' trilobed, a rounded median lobe projeeting 

 in front and supported by two lateral lobes a little further 

 back. Two eyes occur toward the posterior border of the 

 head. In lateral view the snout is bluntly conical, the 

 centriil or prostomial region being nail-like and the mouth 

 opening a little behind tlie tip. A short median tentacle 

 occurs on the prostominm and a brief ridge app'^ars to be 

 continued a short distance backward to end in a small process 

 or tentacle. Tlie body is slightly narrowed anteriorly, 

 is more distinctly diminished posteriorly, and ends in 

 four foliaceous lobes or cirri. It is llattened both doisally 

 and ventrally, the upper surface carrying the branehiie and 

 the ventral surface being marked anteriorly by lines of dark 

 pigment on the terminal region behind the mouth, and with a 

 dark line in the middle of each segnieut-junction for ten or 

 twelve segments following. 



The first segment bears a broad sabre-shaped branchia, 

 ■which overlaps its fellow of the opposite side behind the 

 snout. It has a single lobe, the longer margin being 

 inferior, and a tuft of finely tapered bristles which sliow 

 a narrow margin distally on each side. Above these is a 

 shorter tuft, slightly differing in direction. The second 

 foot has a similar ventral lobe, a tuft of curved bristles, 

 and, in addition, a superior lobe confluent with the branchia 

 and carrying a tuft of longer bristles, finely tapered, but less 

 curved distally. At the tenth foot the ventral lamella is 

 elongated vertically with its upper margin deepest, and 

 separated by a narrow cleft from the dorsal, which fuses 

 with the edge of the bi'anchiie — the whole forming a broad 

 fiat blade. The bristles have the same structure. At the 

 twentieth foot the vertical elongation of the ventral lobe is 

 marked, and the lower half bears a row of hooks, which have 

 a bold curve at the junction of the shaft with the neck, 

 then slightly diminishes upward to the main fang, which 

 makes more than a right angle with the neck, is long and 

 sharp, with a spike above it, and has a wing on each side. 

 The upper dorsal bristles are longer and more slender. At 

 the fortieth foot the branchia is shorter and bi'oadei', 

 and the ujiper grou]) of the bristles much elongateil and 

 very finely tapered. The ventral hooks are similar. 



In 1896 Mcsnil established the genus Ntrinides for 

 De St. Joseph's Ncriue luiitjirosiris, in which the pro- 

 stominm was without frontal processes. The branchite 

 extcndid Iroui the secoutl setigerous segment, and these 



