365 
T)r. liKACii^s Arrongement of the Crustacea, tf’C. 
Spec. 2. Idoiea pelagica. 
I. corpore lineari-ovato, caud4 rotundatti medio dente obso- 
letissimo antennis tertiam corporis longitiidinem aequanti- 
bus. 
Habitat in raari Scotico ; ab aniico R. Stephenson, Arniigeio, cum 
animaliutn copiA^, accepi. 
Mr. Stephenson sent me this species from the Bell Rock, 
and afterwards in the most obliging manner procured for me a 
large log perforated by Limnoria terebrans, which contained a 
vast number of them in the deserted cavities formed by that 
animal. 
Colour when alive ash-gray or fuscous, speckled with darker 
fuscous, and often variegated or mottled with white spots ; legs 
pale. The female seems very rare, as amongst four hundred only 
one occurred. Length one inch and a quarter. 
Spec. 3. Idotea Oestrum. 
I. corpore elongato-ovato, caudd truncate emarginata, antennis 
tertiam corporis longitudinem sequantibus. 
Oniscus CRstrum. Fenn. Brit, Zool. iv. pL 18. Jig. 6. 
Long. Corp. li unc. 
We have never met with a living specimen of this animal, but 
have received it from our liberal friend Montagu, who considers 
it as a mere variety of Entonion; it differs from Entomon in 
wanting the teeth at the extremity of the tail, and having a deep 
notch instead. The antennae, too, are evidently shorter. 
Gen. 19. Stenosoma. 
Antenna exteriores corporis longitudine, articulo tertio quarto 
longiore. Corpus lineare. 
3 B 2 
Spec. 1. 
