326 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 7 



disposed in a single row, making for a hook that is thin, readily lying flat 

 (see also p. 331), 



The 5 genera or subgenera of PECTINARIIDAE are separable as 

 follows : 

 1. Scaphe not sharply set off from the rest of the body; antennular 



membrane not fringed Petta Malmgren 



1. Scaphe sharply set off from the main part of the body; antennu- 

 lar membrane fringed 2 



2. Lateral portions of antennular membrane fused with paleal 

 segment Lagis Malmgren 



2. Lateral portions of antennular membrane free from paleal seg- 

 ment 3 



3. Dorsal margin of cephalic plaque fringed . Amphictene Savigny 



3. Dorsal margin of cephalic plaque entire 4 



4. Uncini with major teeth in a single row Cistenides Malmgren 

 4. Uncini with major teeth in 2 or more rows 



Pectinaria, sensu Malmgren 



The genus Lagis is not known from the Western Hemisphere ; Petta 

 is known only through one species, P. pellucida Ehlers (1887, p. 194), 

 from Florida. Amphictene has been described or reported from the West- 

 ern Hemisphere through 3 species : 



A. auricoma (O. F. Miiller), from Alaska (Moore, 1908, p. 

 353) south to Elkhorn Slough, California (MacGinitie, 1935, 

 p. 694) ; 

 A. guatemalensis Nilsson (1928, p. 46), from the Pacific side of 



Central America ; 

 A. catharinensis F. Miiller (see Nilsson, 1928, p. 43), from Des- 

 terro, Brazil. 

 No representatives of Amphictene have turned up in the Hancock collec- 

 tions. Both Cistenides and Pectinaria are represented by several species 

 (see below). 



In a recent monograph of the family, Nilsson (1928, p. 23) consid- 

 ered 13 species in these 2 subgenera. These included 6 species in Cisten- 

 ides: aegyptia (Savigny), chilensis Nilsson, ehlersi Hessle, gouldiiY trnW, 

 granulata (Linnaeus), hyperborea Malmgren; and 7 species in Pec- 

 tinaria: antipo da Schmarda, australis Ehlers, belgica (Pallas), brevispinis 

 Grube, clava Grube, conchilega Grube, and parvibranchis Grube. 



