120 NOTES ON THE COPOPEDA OF THE 



17. Scolccithrix atlanticus (nov. sp.). $ very large, 3*95 mm. long. 

 Anterior antennae twenty-three-jointed and longer than the whole body; 

 rami of posterior antennre nearly equal ; sensory processes of the anterior 

 foot-jaw both brush and vermiform, a brush process on the posterior 

 foot-jaw ; fifth pair of feet of two segments, distal the longest, with 

 rounded extremity, and one short stout bristle at the apex, and a 

 thick bristle twice as long arising from the inner margin. Feet like 

 Scolecithrix. There may be doubt whether this species should be 

 considered a Scolecithrix or a Xanthocalanus ; the twenty-three-jointed 

 antennae and coalesced head and first segment are more characteristic 

 of the former genus. It is a very large species, and was taken in 300 

 fathoms depth off the west coast of Ireland. 



18. Lophothrix sccurifrons (nov. $2}.). Head with a strong crest, and 

 strongly pointed wing-like expansions of the last thoracic segment; 

 very short abdomen, with large genital segment, with a downward 

 projecting process in front and strong bunches of lateral hairs. Helmet- 

 shaped appendage of head produced anteriorly into a thick rostrum, 

 each ramus ending in a short point. Amalliform (sheaf-like) sensory 

 processes on the anterior foot-jaw, and a similar process on the posterior 

 foot-jaw. Anterior antennae of twenty-four segments reaching the 

 end of the furca. (PL IX., figs. 12, 13, 14, 15.) The animal closely 

 resembles the Scolecithrix securifrons described by Scott {Trans. Linn. 

 Soc), but differs in the segmentation of the anterior antennte and in 

 the possession of amalliform sensory processes apparently absent in 

 Scott's species. Size of ? 4'2 mm. Occurred in the warm area of the 

 north Atlantic. 



Note. — Tlie sub-family Scolecithrichina is conveniently subdivided into the genera 

 Scolecithrix, Amallophora, and Lo}ihothrix. The characters distinguishing each are as 

 follows : — 



1. Scolecithrix. Head usually without crest (only in S. securifrons, Scott) ; anterior 

 antenna nineteen to twenty-four jointed ; sensory processes of anterior and posterior foot- 

 jaws of one kind only (vermiform) ; fifth feet generally present in the $ but always 

 small and of one to three segments ; type species .S'. minor (Brady) and S. danae (Brady). 



2. Amallophora (Scott). Head with crest and helmet-shaped projection ; no epistome ; 

 anterior antenna? of twenty-two joints ; foot-jaws with three kinds of sensory appendages, 

 amallaj, brush processes, and vermiform ; maxilla with seven bristles on the exopoditc, 

 nine on the en(loi)odite, second basal with four only ; fifth feet of two or three segments, 

 with very long inner bristle ; type species Amallophora magna (Scott). 



3. Lophothrix (Giesb.). Head with a crest and helmet appendage, produced into 

 rostrum ending in short spines and not filaments ; anterior antenna twenty-four-jointed ; 

 maxilla with five bristles on the second basal, eight on the eudopodite, nine on the 

 exopodite ; sensory processss of the foot-jaws amallre and vermiform ; fifth feet of two or 

 three segments with one to three terminal spines apical and inner, usually strong epistomal 

 projection; type species L. frontalis (Giesb.). (PI. IX., figs. 41, 42.) 



19. Hcterorhdhdus yrandis (nov. s^;.) (?). The largest known species of 

 Heterorhahdus, attaining a size of 6-60 mm. in length ; the anterior 



