645 



marsupial pouch. Superior antennae slender and elongated, with multiarticulate 

 flagellum. Inferior antennae well developed, though, as a rule, much smaller 

 than the superior ones. Buccal area rather prominent. Anterior lip broad, 

 bilobed ; posterior lip with distinct inner lobes. Mandibles with or without 

 palps. First pair of maxillae without any basal lobe, palp well developed, 

 biarticulate; 2nd pair small. Maxillipeds normally developed, with large 

 pediform palps. G-nathopoda very unequal, the anterior ones comparatively 

 small, and originating far in front, beneath the cephalon ; the posterior ones 

 much larger, and often very differently shaped in the two sexes. Pereiopoda 

 more or less reduced in number, the 2 posterior pairs always strongly deve- 

 loped and prehensile. Metasome and urosome forming together generally a 

 very small nodiform appendage issuing between the bases of the last pair of 

 pereiopoda, and carrying more or less distinct rudiments of limbs (uropoda). 

 Remarks. The forms belonging to this family are easily recognizable 

 by their narrow cylindrical body, which is very flexible, so as to be bent in 

 a complete circle. They are generally found clinging to algae or Hydroida, 

 to which they attach themselves firmly by the aid of the powerfully developed 

 posterior pairs of pereiopoda. The family comprises as yet 10 different 

 genera, of which are represented in the fauna of Norway. 



Gen. 1. Phtisica, Slabber, 1749. 



Syn.: Pro to, Leach. 

 Leptomera, Latr. 

 Naupredia, Latr. 



Body very slender, with no perceptible boundary between the cephalon 

 and 1st segment of mesosome; the 5 succeeding segments elongated, last seg- 

 ment very short. Both pairs of antennae with multiarticulate flagella, the 

 superior ones being, as usual, much the longer. Mandibles with the cutting 

 edge divided into several superposed lamellae, molar expansion obsolete, palp 

 well developed. Maxillipeds with the masticatory lobes smaller than the 

 basal ones. Both pair of gnathopoda distinctly subcheliform and but slightly 

 differing in the two sexes, the posterior ones being much the larger, with 

 the propodos oblong fusiform in shape. All 5 pairs of pereiopoda present^ 

 the 2 anterior ones very slender, antepenultimate pair smaller than the 

 others, with the ischial joint not defined. Branchial lamellae narrow, present 

 on the 2nd, 3rd and 4th segments of mesosome. Urosome with pairs of 

 biarticulate appendages (uropoda). 



85 Crustacea. 



