w 
Dr. Leacn’s Arrangement of the Crustacea, $c. 365 
Spec. 2. Idotea pelagica. 
Į. corpore lineari-ovato, caudá rotundatá medio dente obso- 
letissimo antennis tertiam corporis longitudinem zquanti- 
bus. 
Habitat in mari Scotico; ab amico R. Stephenson, Armigero, cum 
animalium copiä, accepi. 
Mr. Stephenson sent me this species from the Dell 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 eavities 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 (Estrum. 
I. corpore elongato-ovato, caudá truncatä emarginatä, antennis 
tertiam corporis longitudinem »quantibus. 
Oniscus CEstrum. Penn. Brit. Zool. iv. pl. 18. fig. 6. 
Long. Corp. 14 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 Entomon; it differs from Entomon in 
wanting the teeth at the extremity of the tail, and having a deep 
notch instead. The antenne, too, are evidently shorter. 
Gen. 19. STENOSOMA. 
Antenne exteriores corporis longitudine, articulo tertio quarto 
longiore. Corpus lineare. | 
322 E Spec. 1. 
