Ul 

 11. Argissa typica, Boeck. 



(PI. 48). 



Argissa tyjnca,^ Boeck, Crust amphip. bor. & arctica, p. 4.5. 



Syn : ChimseropBis danica, Meinert (male) 



Boily as a rule strongly curved, exhibiting at first sight an unmistak- 

 able resemblance to that of an Ampeliscu. Cephalon exceeding in length 

 the first' 2 segments of mesosome combined, sirbtruncated in front, lateral 

 corners Init little projecting and narrowly rounded. First pair of coxal plates 

 rather large, gradually widening distally, with the edges evenly curved and 

 provided with slender bristles; the 2 .succeeding pairs narrowly triangular in 

 form and rapidly decreasing in size; 3rd pair very small; 4th pair in female 

 of extraordinary size, oval in form, and very slightly emarginated jjosteriorly 

 in its u])per part, the edges evenly curved and smooth, tlio.se in male con.si- 

 derably smaller; the 2 succeeding pairs of moderate size, with the posterior 

 lobe much deeper than the anterior. Last pair of epimeral ])lates of meta- 

 some neai'ly rectangular. Urosome in female (juite smooth above, in male 

 with 2 vaulted transverse expansions, the posterior very large and overhanging 

 the last segment. Eyes rounded in form, each containing 4 small bigeminous 

 lenticular bodies arranged in regular distance from each other, pigment red 

 with a whitish coating. Superior antennse in female about the length of the 

 cephalon and the tir.st 3 segments of mesosome combined, joints of the peduncle 

 regularly diminishing in size, the 1st being aljout as long as tlie other 2 

 taken together, all provided with simple scattered bristles, tiagellum very 

 .slender, about the length of the peduncle, and composed of 7 articulations; 

 accessory appendage very small, scarcely as long as the last joint of the 

 peduncle, biarticulate, terminal joint extremely minute. Same antennae in 

 male a little more slender, flagelliun nearly twice the length of the peduncle, 

 its first 2 articulations fused together into a single rather large joint, provided 

 liosteriorly with numerous transverse rows of fine sensitive cilia. Inferior 

 antennae in female nearly twice as long as the superior, joints of the peduncle 

 narrow cylindric, and nearly smooth, the penultimate one by far the longest; 

 Hagellum scarcely longer than the two oiiter joints of the peduncle combined, 

 and composed of 7 articulations; those of male much more slender and elon- 

 gated than in female, though not quite attaining the length of the body, Ha- 

 gellum about the length of the peduncle and composed of the same number 

 of joints as in the female. (Tuathopoda densely setous, propodos much shorter 

 and narrower than the carpus, dactylus slender and feeble. The 2 anterior 

 ])airs I if jiereiopoda scarcely attaining the length of the gnathopoda and in 

 female almost eutii'ely concealed by the large 4th jiair of coxal jilates. Penul- 

 timate pair of pereiopoda a little more slender than the antepenultimate ones, 



18 b — Crustacea. 



