38 

 Family Rauinidce. 



Lteeidus, De Haan. 



lyreicZits, De Haan, Faun. Japon. Crnst. p. 138 : Dana, U. S. Expl. Exp. Crnst. pt. I. p. 404: Haswell, Cat. 

 Anstral. Crust, p 114 : Henderson, Challenger Anomnra, p. 33 : Alcook, J. A. S. B. Vol. LXV. pt. 2, 1896, 

 p. 294. 



Carapace elongate-obovate, the antero-lateral margins independent and gra- 

 dually convergent ; strongly convex from side to side and slightly convex from 

 before backwards ; smooth and polished, with the regions undefined. Fronto- 

 orbital border less than half the breadth of the carapace. Eyes small ; eyestalks 

 short, broad at base, orbits hardly oblique. 



Antennules about equal in size to the antenna : antennjB with a stoutish 

 peduncle and rather short slender flagellum, the peduncle not concealing the 

 antennulary peduncle. 



Merus of the external maxillipeds a little longer than the ischium. 



Sternum broad as far as the bases of the first pair of true legs, then 

 becoming narrow. Last pair of legs abnormally short and slender, arising well 

 in advance of the penultimate pair. The abdomen in both sexes consists of 7 

 distinct segments. 



Lyreidiis CJianneri, Wood-Mason. 



Lyreidus channeri, Wood-llason, P. A. S. B., August, 1885, p. 104, and J. A. S. B., Vol. LVI. 1SS7, pt. 2. 

 p. 206, pi. i : Alcook, J. A. S. B. Vol. LXV. pt. 2, 1896, p. 294. 



Lyreidus gracilis, Wood-Mason, J. A. S. B., Vol. LVI. 1887, pt. 2, p^ 376. 



The greatest breadth of the carapace — considerably in rear of the front — 

 is a good deal more than half its greatest length, and is about 2^ times the 

 width of the fronto-orbital border. 



The rostrum consists of a simple flat acutely-triangular spine ; on either 

 side of it, projecting beyond it, separated from it by a deep bight, and parallel 

 with its tip, is a long acicular spine forming the external orbital angle. The 

 fronto-orbital region is hairy. 



The gradually convergent antero-lateral borders are about two-fifths the 

 length of the postero-lateral borders, the junction of the two borders being 

 occupied by a long oblique acicular spine ; and nearly midway between this 

 spine and the spine at the external angle of the orbit on either side, is another 

 similar but rather shorter spine. The postero-lateral borders are defined in 

 more than their posterior half by a very fine raised line. 



The surface of the carapace is finely and closely punctulate in all its anterior 

 half, as are also the pterygostomian regions. 



The eyestalks are broad and flat, and taper to the cornea, which has a some- 

 what lateral position and is a little deficient in pigment. The arms have a spine 



