NO. 2 HARTMAN, BARNARD: RENTHIC FAUNA OF DEEP BASINS 157 



Genus MELINNA Malmgren, 1867 



Melinna heterodonta Moore, 1923 

 Melinna cristata heterodonta Moore, 1923, pp. 212-213, pi. 17, fig. 25. 



This species was originally described from off Monterey Bay south to 

 San Diego in depths of 110 to 2228 fms. It is characterized by having 

 18 thoracic setigerous segments. The postbranchial membrane is denticu- 

 lated with 14 to 16 unequally long lobes. The species may be limited to 

 deeper water, whereas M. denticulata Moore (1908) is found more 

 abundantly in shelf and slope depths. The latter has 17 thoracic setiger- 

 ous segments and the postbranchial membrane terminates in fewer ( 7 to 

 8) lobes. 



Another small individual from San Diego trough (Sta. 6090) meas- 

 uring 8.6 mm long, has branchiae nearly as long as the thorax ; they are 

 inserted on a pair of long, broad bases. The thorax consists of 17 setiger- 

 ous segments, as in M. denticulata, but the postbranchial membrane ter- 

 minates in 10-15 short, triangular lobes, irregularly longer and shorter. 

 The large postbranchial dorsal hooks are pale yellow. 



Genus Melinnampharete Annenkova, 1937 



This genus is characterized by having pinnately divided oral tenta- 

 cles. Branchiae number 3 pairs, are cirriform, and inserted in a straight 

 transverse line. Paleae are present but not conspicuous; they terminate 

 distally in an oblique tip. Postbranchial dorsal hooks are absent. Thoracic 

 notopodia number 15 pairs. A dorsal ridge is present between setigerous 

 segments 3 and 4. Nephridia open in segments 4, 6 and 7. A single species 

 is known. 



Melinnampharete eoa Annenkova, 1937 

 Annenkova, 1937, pp. 186-187, 213, pi. 4, figs. 39, 40. 



Small individuals measuring to 15 mm long, without the long bran- 

 chiae, were taken in Santa Cruz and San Clemente Basins. The 3 pairs 

 of branchiae are inserted in a straight line. Paleae are weakly developed. 

 The dorsal transverse membrane is not conspicuously fimbriated. The 

 paleae have oblique distal ends. 



Melinnampharete eoa is previously known from the northwest Pacific 

 Ocean, in 78 to 1600 meters (Uschakov, 1955, p. 364). The species may 

 be considered a deep water and abyssal form. 



