

HIGHER CRUSTACEA OF THE L.M.B.C. DISTRICT. 203 
characteristics as to be sufficient reason for referring it to 
Lysianaz. 
*Lysianax audouinianus, Sp. Bate (Pl. X., figs. 9 and 10). 
II. Two young specimens on Halichondria, dredged in 
thirty fathoms, twenty-two miles §.E. of Isle of Man. 
Length 3mm. Hellert+ has described a form which he 
calls Aristias tumidus, (jun.), Kroyer, but which he says 
differs in some of the mouth organs from the adult. It 
also differs in having an entire telson. But Hansen? says 
that A. tumidus of all authors except Kroyer is not the 
same species as the latter’s, and proposes the name of 
A. neglectus for A. tumidus, Auct. Boeck includes with 
this Lysianassa audouiniana, Bate, but, as Hansen points 
out, this species has an entire telson, while in the genus 
Aristias, Boeck, it is cleft to the base. I therefore refer 
both my specimens and those of Heller to L. audowiniana, 
although they should properly be placed in a new genus, 
as the strongly subchelate character of the first gnathopod 
does not agree with Boeck’s definition of. Lystanassa. 
In my specimens the inner rami of all the uropods are 
minutely toothed on both edges, as are also the outer rami 
on the inner edge, As however it requires a high power 
(4-inch objective) to see this denticulation, it may have 
escaped observation. 
*Hippomedon denticulatus, Bate and Westwood. 
One young specimen, Port Erin, five fathoms. II., E.L. 
Hanser§ points out differences between this species and 
H, holbolli, Ky., with which Boeck unites it. In the former 
the integument is smooth, while in the latter it is reti- 
culate and granulate, The hinder angle of the third pleon 
+ “Crust. &e., Oster. Ungar. Nordpol. Expn.,”’ p, 6, pl. iv., figs. 1—8. 
+ “Videnskabliger Meddelelser Nat. Forening i Kjobenhavn,” 1887. 
§ ‘‘Vidensk. Med, Nat. Forening i Kjob.,” 1887, p. 63. 
