44 



1. Diastylis Rathkei (Kr0yer). 



(PL XXXIII, XXXIV). 

 Cuma Bathkei, Kroyer, Nat. Tidsskr. Vol. 3, p. 513. pi. 5, 6, figs 1730. 



Syn : Cuma angulata, Krayer (adult male). 



Specific Characters. Female: Body more slender than in most other 

 species of this genus, with the anterior division scarcely at all tumefied, and 

 oblong in form. Carapace exceeding the exposed part of the trunk by about Vs 

 of its length, and but slightly vaulted above; frontal lobe armed along the 

 middle with a double row of strong, anteriorly-curving denticles, sometimes 

 crossed by one or 2 imperfect transverse rows, lateral faces below the frontal 

 lobe exhibiting a somewhat varying number of scattered small denticles; pseu- 

 dorostral projection conically produced, horizontal; subrostral corners more or less 

 distinct. Last pedigerous segment with the anterior edge coarsely serrate, lateral 

 parts produced behind to rather large acute processes, extending almost to the 

 end of the 1st caudal segment. Tail somewhat exceeding the length of the an- 

 terior division, segments simple, without any spiniform projections. Eye rather 

 small, though distinct. Superior antennae not very slender, the peduncle scarcely 

 reaching beyond the tip of the pseudorostral projection, 1st ioint about the length 

 of the other 2 combined, and armed at the end inside with a small denticle. 

 First pair of legs scarcely longer than the carapace, basal joint equalling in 

 length the remaining part of the leg, and denticulate in its distal part, the last 

 3 joints of about equal length; 2nd pair with the terminal joint not much longer 

 than the preceding one, both together scarcely exceeding half the length of the 

 antepenultimate one ; 3rd and 4th pair very strongly built and densely setiferous. 

 Uropoda about half the length of the tail, outer ramus rather robust, being con- 

 siderably larger than the inner, though scarcely exceeding half the length of the 

 stem, and densely setiferous along the outer edge and the tip; inner ramus with 

 the 1st joint fully as long as the other 2 combined, spinules of the inner edge 

 about 11 in number (6 of the 1st, 3 of the 2nd, and 2 of the last joint), apical 

 spine strong, mucronate. Telson rather produced, extending fully as far as the 

 stem of the uropoda, its proximal thickened part comparatively short, scarcely 

 occupying more than 1 / 4 of the length of the telson, distal part gradually attenuated, 

 and armed on each side with numerous (about 15) spinules, apical spinules of 

 exactly the same appearance as the lateral. Colour whitish, with a more or less 

 distinct carneous tinge. Length amounting to 16 mm. 



Remarks. This form was first described by Kr0yer in the year 1841 as 

 a species of the genus Cuma, The form subsequently recorded by the same 



