60 MR. F..R. C. REED ON THE GENUS LICHAS. | Feb. 1902, 
Nuttaina [sic], Corydocephalus, Dicranopeltis, Acanthopyge, and 
Dicranoginus. ; 
In the same year M. Schmidt’ recognized the following groups 
among the Ordovician species of Zichas in the Baltic Provinces of 
tussia :—Arges, Leiolichas, Platymetopus, Metopias, Hoplolichas, 
Conolichas, Homolichas, Oncholichas, and a miscellaneous group. 
Dr. Beecher * in 1897 quoted the following genera and subgenera 
as belonging to the family Lichadide :—Jichas, Arctinurus, Arges, 
Ceratolichas, Conolichas, Dicranogmus, Homolichas, Hoplolichas,. 
Levolichas, Metopias, Oncholichas, Platymetopus, Terataspis, Troch- 
urus, and Uralichas. 
In Beecher’s chapter on trilobites in the English edition (1900), 
of Zittel’s ‘Text-book of Paleontology’ (vol. 1, p. 632), Lichas 
alone is given as the type-genus of the family Lichadide, with the 
following subgenera :—<dArges, Dicranogmus, Conolichas, and Cerato- 
lichas. 
Lastly, Dr. Giirich * has recently published his views on the sub- 
divisions of Lichas, and has recognized the following subgenera :— 
Metopolichas (= Metopias), Platylichas, Platopolichas, Leoilichas,. 
Homolichas, Hoplolichas, Conolichas, Platymetopus, Trachylichas, 
Pierolichas, Oncholichas, Echinolichas, Ceratolichas, Henuarges,. 
Plusiarges, Huarges, Liparges, Ceratarges, and Oraspedarges. | 
III. Hisrortcat SumMARY oF THE NOMENCLATURE. 
AcantnopyGr, Corda, 1847 (‘ Prodr. Bohm. Trilob.’ p. 144 & pl. i, figs. 5—7).. 
Type, A. Leuchtenbergii, Corda=Lichas Haueri, Barrande, 1846 (‘ Not. 
Prélim. Syst. Silur.’ p. 73). [Dr. Girich (Neues. Jahrb. Beilage-Band 
xiv, 1901, p. 527) proposes the subgeneric name Huarges for this type. | 
The young of this species Corda included in his genus Dicranopeltis as. 
D. parva | Prodr. Bohm. Trilob.’ p. 148).—The name Acanthopyga was 
used by J. E. Gray in 1838 (Ann. Nat. Hist. vol. i, p. 278) for a genus of 
Lacertilia, 
Arcrinurus, Castelnau, 1843 (* Essai Syst. Silur. Amér. septentr.’ p. 21 & pl. iii, 
fig. 2). Type, L. Boltoni (Bigsby) 1825 (Paradoxides Boltoni), Conrad in 
1838 (Rep. Geol. Surv. N.Y. pp. 113, 118) had propcsed the name Platynotus: 
for the same species. Schmidt in 1885 (‘ Rev. Ostbalt. Silur. Trilob.’ 
pt. ii, p. 51) chose this species as the type of a new group which he termed 
Oncholichas. but the Russian species which he associated with it differ in 
some important particulars (see p. 76) from the type. ; 
ArGes, Goldfuss, 1839 (Nova Acta Acad. Ces. Leop.-Carol. vol. xix, pt. 1, p. 355 
& pl. xxxiii. figs. | a—c). Type, A. armatus, Goldfuss, 1839. 
Arges had, however, previously been given in 1835 by De Haan (* Faun. 
Jap.’ vol. v, p. 21) to a subgenus of Brachyura, and cannot therefore be 
used for a trilobite. . 
[Cerararces, Girich, 1901 (Neues Jahrb. Beilage-Band xiv, p. 531). Type, 
Arges armatus, Goldf. | 
1 *Rev. Ostbalt. Silur. Trilob.’ pt. ii, Mém. Acad. Imp. Sci. St. Pétersb. 
vol. xxxili, no. 1 (1885) pp. 27-40. 
> Amer. Journ. Sci. ser. 4, vol. iii (1897) p. 196. 
’ Neues Jahrb. Beilage-Band xiv (19U1) p. 519. [It has been impossible for 
me to do full justice to Gurich’s article, as it only reached me to-day, after the: 
proots of the present paper had been received.——December 18th, 1901.] 
The name: 
