6 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 121 



5 bristles in row behind rostrum and 1-6 bristles dorsal to posterior 

 process. Lamellar prolongation of selvage with fringe of hairs 

 along anterior and neutral margins of shell. 



First antenna: First joint without bristles; 2nd joint mth 1 dorsal 

 bristle; 3rd joint with 1 ventral and 1 dorsal bristle; 4th joint with 

 1 distodorsal and 2 distoventral bristles; 5th joint with 1 disto ventral 

 bristle having short terminal filaments; 6th joint reduced, with a 

 short distomedial bristle; 7th joint reduced, with 1 short a-bristle 

 %\ath spines, 1 medium b-bristle, and 1 long c-bristle; 8th joint reduced, 

 with 2 long bare d- and e-bristles and 2 long f- and g-bristles. Sensory 

 bristle on 5th joint, b- and c-bristles of 5th joint, and f- and g-bristles 

 of 8th joint with forked tips and few ringed filaments. 



Second antenna: Endopodite single jointed with 1 long hirsute 

 bristle and 1-3 short bare bristles. Exopodite mth 9 joints: 2ud to 

 8th joints each with 1 long bristle; 9th joint with 2-3 bristles. 



Mandible: Coxale endite bifurcate at tip. Basale mth 4 ventral 

 and 3 dorsal bristles. Exopodite elongate wdth 2 terminal bristles. 

 Endopodite: 1st joint Avith 1-4 bristles; 2nd joint Avith 3-4 dorsal 

 bristles, and 2-3 ventral bristles; end joint with 1 long claw, 2 shorter 

 claws, and about 3 bristles. 



Maxilla: Precoxale endite with 3 stout pectinate spines and 2-3 

 bristles; coxale endite with 2 stout pectinate spines and 2 bristles. 

 Endopodite with slender to stout terminal process. 



Fifth limb: Second joint prolonged distally forming long fanglike 

 tooth followed along the inner margin by 3 teeth. Inner margin of 

 protopodite with single endite with 1-2 bristles. Epipodial appendage 

 with numerous bristles. 



Sixth limb: End joint with 7-9 bristles; endites 3-4 in number, not 

 more than 1 bristle in place of epipodial appendage. 



Seventh limb: Terminus with opposing combs. Number of bristles 

 in distal group 4-6, in lateral group 2-8; total number of bristles 6-14, 



Frontal organ: Elongate with or without(?) rings proximally. 



Eyes: Large medial eye and small lateral eyes. 



Furca: Thu"d claw more slender than 4th. Total nimiber of claws 

 6-10; all well-developed claws separated from lamella by suture. 



Distribution. — Atlantic Ocean off Morocco, on Great Bahama 

 Bank, B.W.L, on Continental Shelf off North Carolina and Georgia, 

 U.S.A., Gulf of Naples (Mediterranean Sea). 



Ecology. — The family is benthonic. It has been reported from 

 water with temperatures ranging from about 3° to 29° C, water depths 

 of 6 to 1435 meters, and salinities from about 35 to 38 parts per thou- 

 sand. Specimens have been collected from shelly sand, sandy mud, 

 and calcareous algae. Some environmental factors concerning each 

 species are presented in table 1. 



