POTTS—POLYCH£TA : AMPHINOMIDZ, 365 
Genus EUCARUNCULATA, Malaquin and Dehorne, 1906. 
10. Eucaruneulata grubet, Malaquin and Dehorne*. (Plate 45. figs. 10-11; 
Plate 46. figs. 9, 10. 
Malaquin et Dehorne, Les Annélides de Ja Baie d’Amboine, Rev. Suisse Biol. t. xv. 1906, pp. 358- 
361, pl. 51. fig. 2, pl. 53. figs. 12-15, 17-20. 
(After some hesitation I have decided to put the three specimens of Hucarunculata into 
a single species, though they differ considerably in general appearance, and even in points 
which might fairly be considered as of specific value. A number of Hucarunculate were 
found, on looking through Mr. Crossland’s Zanzibar collection, which partially bridge 
the gap existing between the forms already examined. A fairly continuous series can 
now be arranged with regard to size and possibly concomitant modifications. For the 
sinaller specimens are instituted two varieties, but it is recognised, that they may 
possibly be growth-stages, the typical species being the adult worm. The differences 
between species and varieties are found in the form of the caruncle, serration of the 
ventral setee, and the number of branches on the gills. Though the colour varies, the 
markings are similar throughout.) 
Measurements. Length 104 mm., breadth 7 mm.; no. of segments 73. 
This magnificent annelid at once attracts attention by the elegance of its shape and 
the beauty of its markings. While the buff-coloured ground-colour is well shown on 
the ventral surface, dorsally it is masked by irregular dark longitudinal stripes of a 
bronze colour, and flecks and masses of white or yellow pigment. The longitudinal 
stripes are just faintly discernible on the ventral surface, and the light pigment is 
present in less quantity but arranged in more definite spots. As in most amphinomids, 
the dark pigment is concentrated in front of the bundle of dorsal sete. 
In shape it is not unlike Hermodice carunculata as figured by McIntosh, though the 
dorsum would appear to be more arched and the section less tetragonal. A noteworthy 
character is the prominent development of the beautiful silky bristles, which are both 
longer and more numerous than in the Atlantic form. The anus is located on the 
dorsum of the last segment. 
The caruncle is attached to the first and second body-segments and reaches back to 
the middle of the fourth. In this specimen it is a broadly spreading trapezoidal 
structure, composed of six or seven folds rising on each side from the middle line, 
which is not marked by a median axis. Its breadth as great as its length, its generally 
irregular and spongy character, and the absence of the median axis would appear to be 
characteristic features; but a comparison with other examples, smaller but otherwise 
identical, seems to show this structure of the caruncle to be associated with the greater 
size of the annelid. The folds are swollen wrinkled structures, only displaying their 
secondary pinnate branching on close examination. The second on each side is bifid 
terminally. The whole organ is tinted a soft brown and marked with yellow spots. 
* My own account had already been written and was in the hands of the printers when I came across the 
description of Eucarunculata grubei cited above. This is very detailed and it was judged best to leave the 
succeeding paragraphs as they were. Malaquin and Dchorne described smaller specimens than the one from 
Chagos, and the differences in form of caruncle and set are probably due to varying age. There is little doubt 
that the species is the same in the two cases. 
