1908.] NATURAL SCIENCES OF PHILADELPHIA. 353 



desideratum. While in their more obvious characters the species are 

 very constant, in respect to others they vary greatly. The repre- 

 sentatives of the genus found in this collection are in most respects 

 indistinguishable from the widely distributed T. strcemii as described by 

 European writers. On the other hand the transitional setie of somite 

 VIII and the abdominal uncini present slight but quite obvious differ- 

 ences at nearly every station. It seems probable that this species as 

 usually recognized includes a large number of subspecies. 



The bent setae of VIII vary in the length and shape of the bent limb. 

 The uncini usually have 5 teeth in the series above and surrounding the 

 beak; surmounting these is a second row of 3 smaller teeth, and crown- 

 ing all a single still smaller median tooth. The latter varies in size and 

 in distinctness from the median tooth of the row below, with which it is 

 more or less coalesced; it may even be wanting entirely. The most 

 distinct form occurs on a large example from Station 4247, in which 

 all of the abdominal uncini examined have the median teeth of the 

 second and third rows completely coalesced and that of the first 

 row altogether absent, leaving a gap. The result is that the beak and 

 one nearly equally large tooth occupy the middle line and a large tooth 

 flanked by a smaller one lies on each side of the gap. Most of the 

 specimens are filled with eggs or sperm. 



Stations 4223, Boca de Quadra, southeastern Alaska, 48-57 fathoms, 

 soft green mud; 4244, Kasaan Bay, Prince of Wales Island, 50-54 

 fathoms, green mud; 4247, same region, 89-114 fathoms, green mud, 

 fine sand, broken shells; 4281, Chignik Bay, 42-43 fathoms, green mud. 

 Polycirrus sp. 



An undetermined species of Polycirrus was taken at Kilisut Harbor. 



AMPHIOTENID^. 

 Pectinaria auriooma (Mailer). 



Amphictene auricoma Malmgi-en, Ofvers. Kongl. Vet.-Akad. Forh., 1866, pp. 

 357, 358. 



All of the AmphictenidsB in the collection belong to one species which- 

 is clearly distinct from any of those hitherto recorded in the Pacific. 

 While closely resembling P. auricoma in nearly every respect, there are 

 some points of distinction between these and European examples 

 which may require their eventual specific or subspecific separation. 

 The margin of the cephaUc membrane is more obscurely and much 

 more irregularly dentate; the uncini usually have 5 large teeth, and the 

 series of fine teeth on the inferior process is not continued on to the 

 upper part of the process beneath the lower large tooth; the scapha 



