NOTES ON SOME OF THE POLYCH^TA. 345 



them ; and as for types of bristles, there is nothing of the kind, 

 characters founded on such an assumption being altogether spurious. 

 The fact of the dorsal bristles being shorter or thicker than the 

 ventral, or vice versa, and that of the ventral bristles being cleft or 

 not cleft at the points, cannot be regarded as typical peculiarities of 

 structure, generic or specific. . . . And this, as I conceive, peculiar 

 unfitness of the bristles to furnish a sure and obvious basis on which 

 might be established a natural division of the Polynoidae into numer- 

 ous genera, extends, I think, with equal force to specific diagnoses." 



2. Among the Aphroditidse dredged by the L. M. B. C, 

 are the rare forms, Malmgrenia castanea, McI., and Herma- 

 dion assimile, McI. These seem to merit fuller notice than 

 they have obtained in the general report.* 



(a.) Malmgrenia castanea, Mcintosh, Travis, ZooL Soc, 

 vol. ix, p. 376. 



Localities (by Gwyn Jeffreys). — N. Uist, 90-96 fathoms, 

 1867, and in 1868. 



On Spatangus purpnreus (near mouth), eighty-five 

 fathoms. Off Valentia, in eighty fathoms, and off Blasquet, 

 in a hundred and ten fathoms, off the Channel Islands. 



Six miles north of Great Ormes Head, fourteen fathoms, in 

 ambulacral groove of Astropecten irregularis (L. M. B. C). 



The head was not present on the specimens obtained by 

 the L.M.B. C, but according to Mcintosh, ''the head is 

 slightly pinkish in life, as is also the proboscidian region, two 

 eyes are situated near the posterior border, and two laterally 

 on the anterior prominence. The tentacle is moderately 

 developed, and has a slight enlargement below the tapering 

 tip. The antennae have brownish pigment a little above the 

 base." 



The body is very long, there being about eighty to a 

 hundred segments. Mcintosh states that there are fifteen 

 pairs of scales. The scales, which are " reniform " or 



* See Report on Vermes, p. 144. 



