PLOTOLEPIS NANS. 48 



size; the cirrophores of the first pair of notocirri are smaller than those of the 

 immediately succeeding pairs, while those of the caudal region are in part more 

 markedly reduced, with correspondingly shortened styles, the most posterior 

 ones being smaller than the adjacent elytrophores. The styles of the longer 

 type of notocirri are for the most part remarkably long, those of the first pair, 

 e.g., when laid back caudad, reaching to the twelfth somite, being decidedly 

 stouter and much longer than the tentacular cirri and in the type having an 

 actual length of 3.5 mm. The styles of the second and third pairs of notocirri 

 are missing in all the types, but the cirrophores of these pairs are decidedly 

 larger than those of the first pair, those of the third being largest of all, and the 

 size of the basal scars would indicate that the styles were of proportionate length. 

 The cirrophores of the fourth pair are again reduced but are larger than those 

 of the first pair; in one paratype in which the style on one side is still present, 

 the latter is seen to exceed in actual length that of the first pair, and when laid 

 back, to extend over the eight succeeding somites, reaching thus from its own 

 somite (the tenth) to the nineteenth. The fifth pair of notocirri are abruptly 

 very different from the preceding ones, having an ordinary non-inflated cirro- 

 phore smaller than adjacent elytrophores and bearing a style of ordinary form 

 and size, this extv^nding only to or scarcely beyond the middle of the parapodium. 

 The next notocirri, the sixth, are again of the inflated type, with styles a little 

 shorter than those of the fourth pair, the seventh are again of the reduced type, 

 the eighth again long, and so on. Thus there are the very elongate special 

 notocirri on somites III, VI, VIII, X, XIV, and XVIII (in the type that of 

 the eighteenth is relatively short though long in the paratype) ; short ordinary 

 notocirri on somites XII, XVI, and probably XX. The neurocirri of the first 

 metastomial pair of parapodia are attached at the extreme base of the latter;" 

 they are long and tapered, extending distad beyond the tips of the setae of the 

 parapodium. All succeeding neurocirri attached a little proximad of the middle 

 of parapodium, and short, failing much of attaining the end of the parapodium, 

 in those of the middle region by as much as or more than their own length. 



Elytra are borne on somites II, IV, V, VII, IX, XI, XIII, XV, XVII, XIX, 

 and apparently also in a much reduced condition on XXI. The elytrophores 

 in general are stout and cylindrical and extend dorsoectad from the bases of 

 the parapodium. Most elytra are missing, but a few remain in one paratype. 

 These are all small, having in general a maximum diameter only about twice 

 that of the elytrophore. In outline each is broadly ear-shaped or suborbicular 

 with an indentation on the exterior side and toward the anterior end. They are 



