POLYCH^ETA. 247 



between the anterior segments to such an extent that four pairs of elytra had to be 

 removed in order to expose it (Plate I., fig. 6). The antennae converge from the 

 anterior pinnacles of the head towards the middle line, and then run side by side 

 close together ; one of them may sink down at a lower level, and then one only 

 remains in view. They are subglabrous, being very sparsely and minutely papillose. 

 Schmarda observed one antenna only, which he described as a tentaculum impar 

 erroneously. There is no doubt as to the identification of the present specimen with 

 Schmarda's species ; the only question is whether it is co-specific with Savigny's 

 I. muricata (Grube, ' Ann. Semp.,' 1878, p. 21). 



An elytron from the mid-body shows a concave anterior border, a large gold- 

 coloured outer surface and a smaller pale inner portion directed obliquely forwards 

 and overlapped by neighbouring scales. The whole surface of the elytron is divided 

 up into polygonal, mostly hexagonal areas, and these again into numerous secondary 

 areoles. The main areolation resembles that of Harmothoe dictyophora, but differs in 

 some details ; the areas are largest on the inner (mesial) portion of the scale, smaller 

 along the outer and posterior borders ; the secondary areolation is highly charac- 

 teristic and was noted by Schmarda. Focussing through the superficial secondary 

 areolation, another reticulum, which may be called the interstitial reticulum, comes 

 into view, the meshes of which do not coincide with the former. The interstitial 

 mesh-work shows nodal dilatations with a refringent body in each, like a nucleus, 

 very clear in caustic potash. Proceeding to the pigmented portion of the scale, the 

 surface enclosed by the secondary areoles becomes elevated to form low papillae, 

 which, near the outer border, assume the form of inclined spines. Posteriorly, certain 

 of the primary areas become elevated to form long stout aculeate spines terminating 

 distally in a pair of prominent horns and covered by numerous secondary spines, as 

 figured by Schmarda. The secondary spines become larger distally, so that the 

 main spine sometimes presents a more or less trifid appearance at the summit. The 

 dorsal setae are excessively numerous and bipinnate. The ventral setae show a well- 

 marked subterminal dilatation, a verticillate tract, and a smooth curved apical 

 portion. 



As for Iphione muricata, Grube makes no mention of the secondary areolation of 

 the elytra, a highly remarkable feature ; and he states that the outer and posterior 

 margin of the scale is fimbriated, which is not so in /. peronea. Across the major 

 diameter of the scale I counted about 30 primary meshes, and across one of the latter 

 about nine sharply defined secondary areoles. There are 29 segments, 13 pairs of 

 elytra. The anus is dorsal and is bordered by the last pair of elytra. Schmarda 

 says the last segment has " zwei kleine Endfortsatze," but I cannot see them. The 

 dorsal and ventral cirri, the palps and tentacular cirri are papillose. The tentacular 

 cirri are concealed below the palps in dorsal view. 



A smaller specimen, 5 millims. wide, shows a wide membranous fringe round the 

 outer and posterior border, not yet areolated ; there are no fimbriae ; about 1 7 



