166 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 117 



dactyls small or lacking. Peraeopods 3-5, basal segments broadly 

 expanded, segments 4 and 5 frequently broad, dactyls smaU or lacking. 

 Peraeopod 4 longest, 5 slightly shorter, 3 shortest, Peraeon segments 

 2-6 inclusive with simple, saclike coxal gills. Brood plates variously 

 reduced, small or vestigial on peraeon 3. Pleopods strong, peduncle 

 short, stout. Urosome normal or variously reduced. Uropods nor- 

 mally biramous, 3rd slender, with 2-segmented outer ramus. Telson 

 broad, flattened, entire, deeply cleft or bilobed. Sexes dimorphic, 

 tending to likeness in fossorial species. 



Type genus. — Haustorius Miiller 1775. 



Remarks. — The family Haustoriidae resembles the Phoxocepha- 

 lidae in gross morphology and fossorial habits. The genus Urothoe, 

 usually placed in the Haustoriidae, has several characters common 

 to the two families. Although lacking a hooded rostrum, Urothoe 

 is closer to Paraphoxus and typical Phoxocephalidae in the form of 

 its mouthparts, gnathopods, and peraeopods. The development of 

 raptorial gnathopods, reduced maxillary plates, and weak mandibular 

 molar suggests a carnivorous feeding type in at least some of the 

 Phoxocephalidae, whereas the Haustoriidae are essentially filter 

 feeders and minute particulate scavengers. 



Pontoporeiinae, new subfamily 



Head and body segments of normal width, seldom tumid or produced 

 laterally. Rostrum weak or lacking. Eyes usually present, well 

 pigmented. Pleon not abruptly narrowing beyond peraeon. Uro- 

 some normal, frequently dorsaUy toothed or pUose; postero ventral 

 lappet lacking. Antenna 1 variously geniculate, peduncular segments 

 2 and 3 short. Antenna 2: peduncular segments 4 and 5 not lobate 

 or excessively plumose behind. 



Mouthparts about normal. Lower lip: inner lobes small, outer 

 lobes with pronounced lateral wings. Alandibular incisor and lacinia 

 moderately developed. Maxilliped palp slender, 4-segmented. 

 Gnathopod 1 subchelate; gnathopod 2 subchelate or simple, usually 

 unlike gnathopod 1. Peraeopods 1 and 2 similar, dactyls present. 

 Peraeopods 3-5 : segments 4-5 not expanded, dactyls small or vestigial. 

 Pleopods normal, rami subequal. Uropods 1 and 2 normal, similar, 

 equally biramous, uropod 2 smaller. Uropod 3 large, rami flat, 

 marginally setose, unequal. Telson cleft or bilobed. Sexes dimor- 

 phic, female usually the larger. Brood plates large, moderately 

 developed on peraeon 3. In male, flagellum of antenna 2 elongate, 

 bearing platelLke calceoli; m-opod 3 elongate, natatory. 



