roi'Hl'ODA. 35 



10. X. ATLANTICUS. 

 X. atlrtnticiis, Wolfenden, Jour. Mar. Biol. Assoc., April, 1904. 



Size 2 '5 mm. ; anterior antennae much shorter than thorax and very thick basally, 

 abdominal segments prickly and hirsute, feet very spinulose ; fifth of three segments, 

 distal the largest, with four large articulating spines, two apical, two lateral ; all 

 segments very spinulose ; furcal rami as broad as long, and Re of posterior antennae 

 much longer than A'/. (West of Ireland.) 



11. X. oBTUsrs. 



X. obtusiis, Farran, Ann. Rep. Fish., Ireland, r.in2-o3, pt. ii., App. II. (190">), p. 40. 



Size 2 "4 mm. Furcal rami little longer than broad, anterior antennae reach genital 

 segment, feet very spinulose. Fifth feet, three segmented, spinulose, and with two 

 terminal and two lateral spines on last segment ; second joint longest, and spiuulose on 

 both margins. (Atlantic. Ireland.) 



12. X. PINGOIS. 



X.pinguis, Farran, Ann. Rep. Fish., Ireland, 1002-03, pt. ii., App. II. (1905), p. 40. 



Size 4'5 mm. Head imperfectly separated from thorax ; lateral processes of 

 last segment blunt ; furcal segments slightly longer than broad ; anterior antenna; 

 short, not as long as thorax ; rami of posterior antennae short and broad ; feet spinulose. 

 Fifth feet of three segments, and two lateral and two apical end spines ; surface of 

 third and margins of first (inner) and second (outer) spiuulose. (Atlantic. Ireland.) 



13. X. GREENI. X. MUTICUS. 



X.ijreeni, Farran, Ann. Rep. Fish., Ireland, 1902-03, pt. ii., App. II. (190;>), p. 40. X. muticus, Sars, 

 Bull. Mus. Monaco. 



Size 5'30-G mm. ; last two segments of thorax united, last segment with obtusely 

 triangular margins ; furcal segments short, broader than long; anterior antenna; little 

 longer than budv. Fifth feet small, two-jointed (Sars), or three-jointed (Farran), without 

 spines on inner margin ; last joint with three small apical spines. (Atlantic. Ireland.) 



14. X. XTPICUS. 



Amalli>linr<t fi/ji/nr, Scott, Tr. Linn. Soc. (2), VI. (1*94), p. ;,4. 



Only the <J known ; 27 mm. long ; anterior antennae, twenty segments ; right 

 fifth foot short and three segments, left like that of X. 



VOL. IV. 



