dibles with the masticatory part very narrow and lancet-shaped at the end; palp 

 biarticulate. Maxillse with the lobes rather unequal, both carrying on the tip 4 

 setae. Maxillipeds more or less powerfully developed, the posterior ones having 

 in male a slight palmar projection near the base of the hand. Natatory legs of 

 moderate size, terminal joint of outer ramus in 1st pair with only 2 seta inside, 

 in the other pairs with 4 such seise. Last pair of legs with the proximal joint 

 imperfectly defined from the segment, but carrying outside the usual seta; distal 

 joint somewhat tapered distally and ciliated on both edges, apex provided with 2 

 curved seise, generally accompanied inside by a small bristle. 



Remarks. This genus, which is the type of the family Ascomyzontidas, 

 was established in the year 1859 by Thorell, to comprise a form found by him 

 parasitic in the branchial cavity of Ascidians. In the very same year Boeck 

 established his genus Aster oclieres, which has turned out to be identical with 

 Thorell's genus. Although Boeck's paper seems to have been published a 

 little prior to Thorell's Monograph, it appears to me that the generic name 

 proposed by Boeck can scarcely be admitted, because the species of this genus are 

 by no means exclusively parasites of Asterids, but are found to infest many other 

 invertebrate animals. For the same reason, of course, the family-name Aster 'ocheridce, 

 proposed by Giesbrecht, ought to be rejected. Brady has confounded this genus 

 with the genus Artotrogns of Boeck, which in reality belongs to quite a different 

 family, and one of the species (A. latum) has moreover been referred by that 

 author to his genus Cydopicera. The present genus seems to be very rich 

 in species. In the following pages will be described 6 different species belonging 

 to the Fauna of Norway. 



49. Ascomyzon asteroeheres, Boeck. 



(PL LI & LII). 



Asteroeheres Lilljeborgi, Boeck, Tvende nye parasitiske Krebsdyr. Chr. Vid. Selsk. Forb. f. 1859, 



p. 6, PL II. 



Specific Characters. Female. Anterior division of body very broad and 

 flattened, its greatest width fully equalling the length. Cephalic segment exceedingly 

 large, being more than twice as long as the 4 succeeding segments combined, and 

 almost semicircular in outline; lateral edges not inflexed ; rostrum imperfectly defined, 

 and only represented by a slight convexity below the front. Epimeral parts of the 

 trunk-segments expanded laterally and acutangular behind. Penultimate segment, 

 as usual, much smaller than the preceding one; last segment still smaller. Tail com- 

 paratively short, not nearly attaining half the length of the anterior division, and 



