THE CRUSTACEA OF NEW JERSEY. 273 



small, lateral, outer branch short, unguiform, almost obsolete and 

 inner branch linear. 

 A sing'le g-enns. 



Genus LIMNORIA Leach. 



Limnoria Leach, Edinburgh Encyclop., VII, 1813, p. 433. Type Limnoria 

 terebrans Leach, monotypic. (Not consuUed).^ 



Body oblong, rather convex above, with segments sharplv 

 marked off from each other.. Cephalon comparatively short, 

 blunt in front, and buccal mass very prominent below. First 

 segment of mesosome longer than other one, partly advancing 

 over cephalon. Coxal plates on succeeding segments rather large, 

 deflexed, and posterior ones triangularly produced. Five anterior 

 segments of metasome with well developed laterally projecting 

 epimera, and terminal segment broad, flattened above. Eyes 

 lateral, wide apart. Antennae with rather short flagellum. Man- 

 dibles very strong, cutting-edge ending in conically compressed 

 chisel-shaped point, no molar expansion and palp rather small. 

 Anterior maxillae with masticatory lobe conically tapering and 

 coarsely spinous at tip, basal lobe narrow, turned anteriorly, and 

 with three short ciliated apical setse. Posterior maxillae end in 

 three setiferous lobes, innermost representing masticatory lobe. 

 Maxillipeds slender, with basal part rather elongated and narrow, 

 masticatory lobe well developed, and palp of five flattened joints, 

 lanceolate epignath turned anteriorly. Anterior pairs of legs 

 somewhat shorter than posterior, dactylus in all pairs inside with 

 a secondary claw-like projection. Pleopoda with lamellar rami, 

 and excepting last pair fringed with setae. Uropoda with outer 

 ramus short and unguiform, and inner linear. 



Species about three, and including peculiar boring isopods 

 whose destruction of timber that has been submerged, and pile 

 work, has long been known. 



^ In Trans. Linn. Soc. London, XI, 1815. p. 354, the only species is 

 Limnoria terebrans Leach. 



18 MU 



