MACRUHA, STOMAPODA. 
185 
Hagen has published a very elaborate monograph of the Ame- 
rican Astacida (written in 1868, and issued as an illustrated 
catalogue of the Mus. Comp. Zool. at Harvard College, no. iii. 
1870, pp. 1-109, pis. 1-11, imp. 8vo). He points out accidental 
variations and differences of age and sex, and states that in 
most species of Cambarus there are two forms of the males, one 
retaining in advanced age the articulation and shape of the first 
abdominal legs proper to the young specimens, while the other 
loses this articulation. He urges the generic difference between 
the American Cambarus and the Old-World AstacuSj and states 
that all freshwater crayfish of N. America east of the Rocky 
Mountains belong to the former, and all living in California, 
Oregon, and British Columbia to the latter of those genera. 
The following species of American Aetacidcd are observed and described by 
him : — 
Cambarus. Group 1 : acutus (Girard), clarkii (Gir.), pi. 4, troglodytes (Lee.), 
hlandingi (Harlan), fallax, sp. n., Florida, lecontii, sp. n., Georgia, Ala- 
bama, Florida, spiculifer and angustatus (Lee.), versutus, sp. n., Alabama, 
penicillatus (Lee.), pellucidus (Tellk.), pi. 0. 
Group 2: C. lancifer, sp. ii., Mississipi, affinis (Say), pi. 6, virilis, sp. n., 
pi. 8, from Canada to Texas, idaciduSj sp. n., Tennessee, Illinois, Texas, 
juvenilis, sp. n., Kentucky and Osage H., propinquus (Girard), ohscurus, sp. n,. 
New York, rusticus (Girard), immunis, sp. n., hand, pi. 8. fig. h, Illinois and 
Alabama, extraneus, sp. n., Tennessee R. 
Group 3 : C. hartoni (Fabr.), rohustus (Gir.), ohesus, sp. n., pi. 9, from 
Lake Michigan to New Orleans, latimanus (Lee.), advena (Lee.), pi. 7, and 
carolmus (Erichs.). 
Astacus gambeli (Gir.), pi. 11, nigrescens, trowbridgii, pi. 10, and klamathen-' 
sis (Stimps.). 
The first abdominal legs of the males, the antennal lamina, epistoma, and 
external spine of the antennae of many of these species are figured, pis. 1-3. 
Astacus subgrundialis, clienoderma, and brevif creeps, .spp. nn.. Cope, P. Am. 
Phil. Soc. xi. pp. 606-607, fossil, from the freshwater territory of Idaho, may 
be mentioned here as most nearly allied to recent American spp. 
Paneus P Zoea-like larva described by A. Dohrn, Z. wiss. Zool. xxi. p. 876, 
pis. 29 & 30. figs. 64-61. 
STOMAPODA. 
Sars (' Carcinologiske bidrag til Norges Fauna/ i. Hefte, 
Christiania, 1870, 4to, pp. 64, pis. 5) has commenced a mono- 
graph of the Norwegian My sides, containing ^ concise account 
of the many peculiarities of that family, and accurate descriptions 
of 3 genera and 8 species. 
He distinguishes the genera of the Mysides as follows : — 
1. All pleopods of fS different from those of natatory, 2 branched. 
Molar process of mandibles distinct. 
Incisive lobes of 1st pair of maxillae 3. 
Marsupium of ^ formed by the basis of only the posterior 4-6 feet. 
