Sessile-erjed Crustaceans, 325 



It may liere bo meiitioucd that Talorchestia diemenensiSj 

 Haswcll, 1880, a Tasmanian species, ought to be refeired to 

 Orchestia^ since both the figure and the description sliow that 

 the first gnathopod in the female is not simple but sub- 

 chehate, that is to say it has tlic precise character which sepa- 

 rates Orchestia from Talorchestia. 



The new species, Talorchestia brito, has the head truncate 

 in front, the pera3on only moderately widened, the pleon 

 narrow, with the hind corners of the third segment squared. 



The eyes are largo, irregularly rounded, and conspicuously 

 white, with the black pigment more or less discernible beneath. 



The Male. — Tiie upper antennaj scarcely reach the end of 

 the penultimate joint of the peduncle of the lower ; the three 

 joints of the peduncle are nearly equal in length, or the 

 middle joint is slightly the longest ; the flagellum of seven 

 joints is less than half the length of the peduncle. In the 

 lower antennae the third joint has a lobed terminal margin ; 

 the fourth joint is not very much shorter than the long fifth 

 joint ; the flagellum has thirty or more stout but short articu- 

 lations. 



The first gnathopods : The side-plates are narrow, some- 

 what folded, directed forwards. The first free joint is narrow 

 at the neck, with the front margin straight, the hinder convex ; 

 the fourth joint or wrist is not much shorter than the first, 

 distally widened, near the distal end of the hind margin 

 having a pellucid bubble-like process ; as this projects among 

 various spines, the impression produced at first sight was that 

 of an actual bubble of water entangled among the spines. The 

 hand is much shorter than the wrist, more spiny, and having 

 a similar but shallower bubble-like process, which, by oftering 

 something for the finger to close against, renders it sub- 

 chelate. The finger is short, with a small upright spine on 

 the inner margin and a small rounded projection at the base 

 of the nail. 



The second gnathopods : The side-plates are large, rhom- 

 boidal, with a slight emargination at the upper part of the 

 hind margin. The long first joint widens abruptly from the 

 narrow neck, its width again diminishing towards the distal 

 end ; the oblong third joint is scarcely so long as the second j 

 the fourth or wrist is quite insignificant in size and almost 

 coalescent with the hand, which is of great length and 

 breadth, an irregular oval, abruptly narrowed at the insertion 

 of the long, powerful, and distally bent finger. The palm 

 margin is fringed with numerous spines, its edge only micro- 

 scopically crenulate ; the closed finger hugs it closely, except 



