344 THE REY. T. R. R. STEBBING ON 
MALACOSTRACA. 
BRACHYURA. 
Tribe CYCLOMETOPA. 
Fam. ACANTHOCYCLIDZ. 
1852. Cyclinea Dana, U.S. Expl. Exp. vol. xiii. p. 294. 
1886. Cyclinea Miers, Rep. Voy. ‘ Challenger,’ vol. xvii. pt. 49, 
p. 208. 
1898. Acanthocyclide Rathbun, Pr. U.S. Mus. vol. xxi. p. 597. 
1899. Acanthocycline Alcock, J. Asiat. Soc. Bengal, vol. xvii. 
pt. 2; p. 96. 
Alcock accepts Dana’s legion as a subfamily of the Cancride, 
with the definition, ‘‘ Carapace subcireular: front ending in a 
triangular point. Hpistome short, sunken, completely concealed 
by the external maxillipeds which also completely cover the buccal 
orifice. Antennal flagella absent.” The second character must 
be modified for the specimens referred to A. albatrossis, as in them 
the front is not triangular. 
Gen. AcantHocycius M.-Edwards & Lucas. 
1844. Acanthocyclus Milne-Edwards & Lucas, D’Orbigny’s Voy. 
Amer, Merid. vol. vi. pt. 1, p. 30. 
1849. Acanthocyclus Nicolet, Gay’s Hist. Chile, Zool. vol. ii. p. 176. 
1898. Acanthocyclus Rathbun, Pr. U.S. Mus. vol. xxi. p. 597 
(with further synonymy). 
ACANTHOCYCLUS ALBATROSSIS Rathbun. 
1861. Acanthocyclus gayi Strahl, Monats. Ak. Wiss. Berlin, July 
25, 1861 (1862), p. 713, pl. 
» Targioni-Tozzetti, R. Ist. Stud. super. 
Firenze, vol. i., Crost. della Magenta, 
p- 95, pl. 7. fig. 1, a-f. 
1898. A. albatrossis Rathbun, Pr. U.S. Mus. vol. xxi. p. 599. 
Miss Rathbun distinguishes three species of the genus—the 
original A. gayi M.-Edwards & Lucas, 1843, renamed 4. villosus 
by Strahl in 1861, Strahl’s A. gay, for which preoccupied name 
A. albatrossis 1s substituted, and A. hassleri, discovered by 
Dr. Faxon, but by his wish described and named by Miss Rathbun, 
who remarks that “the general appearance of the three species 
is much the same,” but that the differences are constant. Of 
these eleven are tabulated, and, granting in each case the con- 
stancy of the combination, the specific distinction may be justified. 
Taken separately, many, even most if not all, of the differences 
relied on, have a rather untrustworthy appearance. Thus the 
front is entire in gayi and hassleri, faintly bilobed in albatrossis ; 
the dactyli of ambulatory legs are long, little curved in the last, 
short, much curved in the other two; both carapace and legs are 
very hairy in gayi, less hairy in both the others, which again have 
the carapace tuberculate, whereas in gayi it is almost smooth ; 
1877. " 
