Gatty Marine Laboratory^ St. Andrews. 167 



thicker, are developed. The shaft dilates in its progress 

 upward, then gradually diminishes to the sliglitly curved tip, 

 Avhich is rather blunt. At the twentieth bristled foot the 

 bristles are still longer but more slender, and two crotchets 

 are present ventrally, whilst dorsally there are four con- 

 siderably stouter, and. the bristles are very long, stretching 

 far beyond the body. A considerable number of bristles 

 occur ventrally between the hooks, whilst there are three 

 dorsally. At the fortieth foot (PI. VI, fig. 5 d) four large 

 crotchets are present in each division — now closely approxi- 

 mated, the ventral being shaped like a scapel set in its 

 handle, with a slight constriction and bend at the end of the 

 handle ; both shaft and tip are longitudinally striated. The 

 dorsal crotchets still are the stronger (PI. VI. fig. 5 e) and 

 the tip (or blade) is more distinctly curved. Four long 

 bristles occur between the third and fourth (that is, toward 

 the ventral edge) ; whilst ventrally two bristles lie between 

 the first and second and two between the second and third. 



These posterior crotchets differ from those of C. setosa in 

 their great size and in the absence of longer intermediate 

 forms, as well as in their occurrence anteriorly. 



Ch(Etozone Z. 



A fragment of the posterior end of a form not hitherto seen, 

 and having the shape of a gradually widening and spathulate 

 tail with the broad end posteriorly. The posterior border is 

 bluntly rounded, with a median ridge dorsally and ventrally, 

 the former curving downward to terminate in the ventral anus 

 which has a peak anteriorly. The region in front of the broad 

 tail is considerably narrower, the dorsal surface being rounded 

 and the ventral flattened. The segments are numerous and 

 narrow, and have dorsal and ventral tufts of slender 

 capillary bristles (PI. W. fig. 6 a) of a pale yellow colour 

 and nearly straight. It was procurved in the ' Porcupine ' 

 Expedition of 1870, no locality being given. 



A peculiar form, which may temporarily be termed Cirra- 

 tulispio, was dredged in the 'Porcupine^ Expedition of 1869 

 in 378 fathoms in sticky mud off the coast of Ireland. The 

 mud contained fragments of foraminifera, coccoliths, and 

 sandy debris. 



The head (PI. VI. fig. 7) is bluntly conical and the sides 

 of the cone slightly hollowed. A pair of slender tentacles 

 pass from the bristled segment immediately behind, and 

 therefore apparently posterior to the buccal ring. 



