fcRtrSTACEA. 
295 
Pedes ^iiarti {>arid ceteris multo minores et debiliores; articulo ultimo 
brevi minimeque unguiformi, setis 2 apicalibiis instructo. Pedirni paria 3 
posteriora angustata, posteriora versus longitudine crescentia, articulis tix 
dilatatis, ultimo setis 2 inasqualibus terminate j eorum striictura ad natan- 
dum parum apta esse videtur. Operculum pleonis magnum, pleon infra fere 
omnino obtegens, crista instructum mediana setisque brevibus marginalibus. 
Pleopodum par posterius perlongum et angustatiun, simplex, biarticulatum, 
articulo ultimo brevi. 
Of this genus there is but a single species, Macrostylis spinifera. 
The structure of the three posterior pairs of pereiopoda is often clearly and 
strongly defined in Eurycope, whereas in Macrostylis their character aS 
swimming-appendages can hardly be sustained. The general size of this 
animal is from 1| mm. to 2^ mm., but specimens of Eurycope cornuta have 
been taken 3 mm. in length. 
AsSELLIDvE. 
In this same memoir Hr. Gr. O. Sars describes also a new 
genus of Isopoda nearly allied to that of Munna, that he thinks 
the type of a family. 
Pleuracantha. Corpus anticum (cepbalon et pereion) valde dilatatum fet 
depressum, segmentis 4 anterioribus lateraliter angulatis et spiniferis, pos- 
terioribus 3 antecedentibus multo angustioribus, partibus lateralibus obtusis 
posticeque vergentibus. Cephalon sat parvum, subpentagonale, antice in 
medio acute productiim. Oculi nulli. Pleon segmento unico magno ad basin 
constricto apice obtuso acuminato constans. Antenn£e mediocres, subsoquales, 
valde flexuosae, pedimciilo superiorum bi-, exteriorum 7-articulato. Mandibulse 
attenuatfe, apice oblique truncate inque dentes 4 diviso; processu molari 
omnino nullo; palpus mandibularis minimus, indistincte biarticulatus, dentibus 
2 et setis 2 intermediis terminatus. Maxillipedum articuli ultimi 2 elongati, 
nullam chelam formantes. Pedes primi paris robustissimi, subchelifornies, 
articulis ultimis valde incrassatis ; ungue terminali forti, ad basin dentibus 
nonnullis validis armato. Pedes sequentes sat longi, omnes striictura sequali, 
posteriora versus parum longitudine crescentes ; ungue instruct! longo termi- 
nali. Operculum pleonis magnum, apice acute producto. Posteriora pleopoda 
brevissima, parum extra marginem segment! pleonis prominentia, biramosa, 
ramis imequalibus, uniarticulatis. 
Of this genus there is one species, Pleuracantha rtihicunda^ sp. n., taken in 
the Gulf of Christiania in from 10 to 16 fathoms. Its colour is light red, and 
its length, which is that of a female, about 1^ mm. 
Jccra waJiishiana, sp. n., Spence Bate, Proc. Zool. Soc. 1864, p. 667, from 
Esquimau llaibour, Vancouver’s Island. — Jcrra Jilicornis, sp. n., Grube, Insel 
Lussin, p. 76, from Lussin. 
Sphasromid^. 
Among the freshwater Crustacea described by Taramelli (Atti della 
Societa Italiana di Scienze Naturali, vol. vi. p. 366) is Sphecroma fossarum 
(Martens), which he has found at Foro Apio. It differs from S. serratum, 
(Fabr.), in colour, in being much less in size, and in having small tubercles on 
the posterior caudal margin. 
