ON POLYCHAETA FROM THE N.E, PACIFIC. 955 
51. Polycheeta from the N.E. Pacific : The Cheetopteridee. 
With an Account of the Phenomenon of Asexual Repro- 
duction in Phullochetopterus and the Description of Two 
new Species of Cheetopteridee from the Atlantic. By 
F. A. Porrs, M A., Fellow of Trinity Hali, Cambridge, 
and Balfour Student of the University *. 
[Received May 30, 1914; Read November 24, 1914. ] 
(Plates I-—VI.7 and Text-figures 1-13.) 
INDEX. 
Page 
Introduction ......... Raa nsasiaceciae MAL Re GOD 
Diagnosis of Family anal Table of Gane Mek nes eee OOO 
Mesochetopterus, gen. n. 
IDrEeANOSaS Oe Creams Bal INGOTS coooncaanosenoocoscasansueadsonsaugaeod  SETl 
MENGar LOTtuSPeNee -osene Coenen eee ss oe eo aks ean Nae cst t eden OS 
BY Ee DU CORA LD S| Den Oe SRO nae San pod ban ChURE a ee EOrp: Ree ena Eo eee Ce naa ced 963 
The Position of Mesochetopterus in the Family .................. 967 
Telepsavus G. Costa. 
Relepsauussspey ayseey ccc see ence one antics sec dae ee eevaceeniesoy LOOS 
Phyllochetopterus Gr. 
P. prolifica, sp. n. (with an account of asexual reproduction 
in the species) ......... BeoontLE cen 
Some Points in the Woupholosy of ihe hetoptaiias ceAedess 981 
Description of a new Species (P. anglica) from British Waters, 
and a Comparison of those ee. which form True 
Colonies ....... 984, 
Remarks on the Gener anise fopten US serail ep, lnctates 
LCE TULS Mee nee a ae cay ett Mn 7d) 2, Aetna ie thSoklees tesa Meee OOO 
INTRODUCTION. 
The Cheetopterids found in the coastal waters of the Gulf of 
Georgia and Puget Sound, though the species are few in number, 
are very widely distributed and remarkably interesting in their 
biology and morphology. My observations were made on three 
species, all of which appear to be new :— 
Mesochetopterus taylori, gen. et sp. n. 
Phyllochetopterus prolifica, sp. 0. 
Telepsavus sp. 
Of these Mesochetopterus partly bridges the gap between 
the remarkable form Chetopterus and the other members 
of the family. Phyllochetopterus prolifica possesses a type of 
asexual reproduction which is now described for the first time 
in the Polychetat. T'elepsavus is a genus hitherto only known 
* Communicated by the SecRETARY. 
+ For explanation of the Plates see p. 993. 
{ A preliminary note on this phenomenon was published in Rep. Brit. Assoc, 
Ady. Science, 1912, Dundee, p. 513. 
