155 



Fam. 1. Ligiidae. 



Characters. — Body oval, more or less convex above, with the lateral parts 

 of the segments lamellar. Cephalon without any lateral lobes, frontal part roun- 

 ded and not distinctly defined from the epistome. Eyes well developed or want- 

 ing. Antennulse with the last joint very small and without distinctly developed 

 sensory filaments. Antennae well developed, with multiarticulate flagellum. Buccal 

 mass rather prominent. Mandibles with the molar expansion large and broad, 

 exhibiting a finely-fluted, triturating surface. Inner masticatory lobe of the an- 

 terior maxillae sith 3 thick, hairy bristles. Posterior maxilla with 2 similar bristles 

 inside. Maxillipeds with the terminal part distinctly 5-articulate, masticatory 

 lobe truncate at the tip, epignath rather short. External sexual appendages in 

 male double. Inner ramus of 1st pair of pleopoda of a similar structure in the 

 2 sexes, that of 2nd pair in male terminating in a long stylet, slightly dilated 

 at the tip ; opercular plate of pleopoda without air-chambers. Uropoda freely pro- 

 jecting behind, both rami styliform. 



HemarJes. — In the restriction here adopted, this family comprises as yet 

 5 genera, viz., Ligia, Ligidium, Jithanetes, Styloniscus and Stymphalus, all of 

 which are distinguished from the other Oniscoida, among other things, by the 

 multiarticulate antenna! flagellum, by the double external sexual appendages of the 

 male, and by the inner ramus of the 1st pair of pleopoda in male not being 

 transformed into copulative organs. Moreover the wholly exposed uropoda may 

 serve as an easily recognisable distinguishing character. Of the above-named 

 genera, the first 2 will be treated of below. 



Gen. Ligla, Fabricius, 1798. 



Generic Characters. — Body regularly oval, or oblong oval, moderately con- 

 vex . above, with the metasome not abruptly contracted; last segment rather broad 

 with distinct epimeral plates. Eyes large and convex. Antennulae very small, 

 with the last joint rudimentary, nodiform. Antennae rather strong and elongated. 

 Mandibles with a ciliated lappet and numerous penicils behind the cutting part. 

 Maxillipeds comparatively short and stout, with the terminal part rather expanded, 

 epignath rounded. Legs gradually increasing in length posteriorly, dactylus dis- 

 tinctly bi-unguiculate. Opercular plate of uropoda sub-branchial. Uropoda more 



