68 



into an oblong, rectangular lobe reaching beyond the end of fourth joint and with a few strong 

 setse along the inner margin ; the sum of the following five joints somewhat shorter than the 

 second joint and these joints besides very slender and nearly naked, only a couple of setae 

 being inserted on the sixth joint; claw short but very distinct. 



Gnathopods (fig. 5_^) slender, with a single seta only on the sixth joint; seventh joint 

 unusually long, a little shorter than the fifth, terminating in a slender claw; second joint of 

 the exopod very broad, rounded. The thoracic legs (figs. 5 a and 5//) of very moderate length 

 and very slender ; sixth joint with a single, transverse articulation a little beyond the middle ; 

 seventh joint long with a fine claw; the exopod with the second joint large, very broad and 

 rounded. Uropods slender; both rami without spines but with extremely long setse along the 

 inner margin and on their distal end; endopod only rather little shorter than the exopod, with 

 the otocyst well developed. Telson short. 



Remarks. — Though the adult male is unknown it may be considered as certain that 

 it has the pleopods well developed. This curious type is to be referred to the Erythropini, as 

 it is allied to Longithorax Illig, Chunoniysis Holt & Tatt., desaromysis Ortm. and Arachno- 

 mysis Chun. In Longitliorax the antennal squama is well developed; in Ccssaromysis it is small, 

 styliform and near its insertion a spiniform process originates; in CImnomysis and AracJuionixsis 

 this process is present, while the squama is wanting as in Gymnerythrops^ but in this genus 

 the process is wanting. In Longiiliorax the last thoracic segment is considerably elongated, and 

 this structural feature is still more developed in Gymnerytlirops. The gnathopods and thoracic 

 legs in Gynifierythrops show much resemblance to those in Longithorax \ in both genera the 

 sixth joint of the thoracic legs has only a single secondary articulation : it is the distal, vertical 

 articulation which has been preserved, while the more proximal, oblique, secondary articulation 

 found in most genera of the tribe Erythropini is wanting. It may be inserted here, that in 

 Ccesaromysis and Arachnomysis the sixth joint of the thoracic legs has two articulations, but in 

 the latter, and according to Ortmann's figure also in the former, genus both articuladons are 

 vertical or nearly so. It is already stated, that Gymnerytlirops is allied to Longithorax in the 

 structure of the thorax and the thoracic legs, but it differs in having no antennal squama and 

 in the mandibles, the length of the carapace, the uropods, etc. 



40. Gymncrythrops anoiuala n. sp. PI. X, figs, ^a — 5 /&. 



Stat. 138. August 3. Anchorage on the east coast of Kajoa-island. 66 m. Townet. i specimen, 

 an immature female. 



Stat. 144. August 7/9. Anchorage North of Salomakiee-(Damar-)isIand. 45 m. Plankton. 2 speci- 

 mens, both immature females. 



Description. — The frontal plate (fig. 5^) at the base as broad as the carapace, 

 about twice as broad as long, with the lateral margins oblique, the front margin nearly straight 

 and transverse on both sides of the narrow rostrum and about half as long as the basal breadth 

 of the plate ; the antero-lateral angles are rounded ; the rostrum named is somewhat long and 

 narrow, nearly spiniform ; the margins of the plate are bent a little upwards. The antero-lateral 

 angles of the carapace behind the frontal plate produced into a long and robust, spiniform process 



