i82 REPORT OF NEW JERSEY STATE MUSEUM. 



up a new one. It seems, however, to be capable of constructing 

 a tube for itself, when it cannot find suitable ones ready made.- 

 It contributes very largely to the food of many fishes, such as 

 scup, pollock, striped bass, etc. 



Pajiiily POXTOPOREIID.^. 



Form of body various, compressed to tumid. Cephalon not 

 produced anteriorly in form of hood. Coxal plates moderate 

 in size, generally fringed with bristles, those of fifth pair bilobed. 

 Metasome generally well developed, with large epimeral plates. 

 Urosome short and stout. Superior antenna usually shorter 

 than inferior, with an accessory appendage, and joints of pe- 

 duncle sharplj defined. Epistome not at all projecting. An- 

 terior lip forms simple rounded prominence and posterior lip 

 quadrilobate, inner lobes small but well defined. Mandibles 

 comparatively short, thick, with greatly expanded masticatory 

 part, cutting-edge divided into two superposed lamellae, and 

 large protruding molar expansion, triarticulate palp more or 

 less elongate. Maxillje and maxillipeds as usual. Gnathopoda 

 comparatively small and feeble, generally imperfectly subcheli- 

 form, or sometimes approach chelate form. Three posterior 

 pairs of perseopoda mostly dissimilar, adapted for burrowing in 

 loose bottom deposit. Branchial lamellae ample. Incubatory 

 lamellae slender, fringed at tip with long curved setae. Pleopoda 

 usually well developed, especially in male. Uropoda biramous, 

 last pair unlike preceding pairs in structure. Telson flattened, 

 more or less deeply cleft. 



Genera about nine, though only one in our region. 



Genus HAUSTORIUS P. L. S. Miiller. 



Haustorius P. L- S. Miiller, Phys. Belust. Microps. Wahrn. Slabber, Niirn- 

 berg, 1775, p. 52. Type Oniscus arenarms Slabber, monotypic. 



Lepidactylis Say, Journ. Acad. Nat. Sci. Phila., I. 1818, p. 380. Type Lepi- 

 dactyUs dytiscus Say, monotypic. 



Lepidactyliis, auct. 



Pterygocera Latreille, Regne An. Cuv., IV, 1829, p. 124. Type Oniscus arena- 

 fins Slabber, monotypic. 



