248 
cc;leopte ra. 
these) ; C. hrevis^ Aube, also abundant in Japan, has the punctuation 
of head and thorax ahke in both sexes ; other species are probably 
confused under the name oi Hydaticus vittatus ; H. rufulus, Aube, is 
queried as not conspecific with II. leant! er ; H. grammicus, Germ., occurs 
in Japan : D. Sharp, Tr. E. Soc. 1873, p. 47 et seq. 
Dytiscus marginalis, E. A. Schafer, Phil. Trans, clxiii. pp. 429-443, 
pi. xxxiii. fully discusses the minute structure of the leg-muscles, regard- 
ing the less strongly refracting intermediate substance which pervades 
the whole fibre, as the contractile, irritable, and essential part of the 
muscle ; and considering the more refracting substance to have merely a 
passive function. A review is given of the recent literature of the 
subject of striped muscular fibre. Highly magnified portions of the 
muscle are figured in rest and contraction. 
Dytiscus latissimus and marginalis infested by Hydraclina geographica, 
Mull. ; V. Frauenfeld, Yerh. z.-b. Wien, xxiii. p. 7. , 
Acilius simplex and latiusculus, Lee, and ahbreviatus, Aube, =semisul- 
catus, Aube, varr,, and a var. oregonensis is described ; Thermonectes 
laticinctus, Lee, = hasilaris, Harr., var., and a var.' intermedins is 
described from California ; T. nigrifasciatus, Aube, = ornaticollis, Aube, 
var. ; Graplioderes fasciicollis, Harr., = cinereus, L., not zonatus^ F. ; 
Hydaticus cinctijjennis, Aube, = himarginatus^ Say ; Dytiscus latissimus, 
L., occurs (? accidentally) in Canada ; D. diffinis, Lee, and parvulus. 
Mots., = confluens, Say ; D. sublimbatus, Lee, = cordieri, Aube ; G. R. 
Crotch, I. c. pp. 401-408. Acilius maccullochi, K., = mediatus, Say; J. 
L. Leconte, P. Ac. Philad. 1873, p. 326. 
Hydaticus piciventris, Thoms., occurs in Germany ; Kraatz, B. E. Z. 
xvii. p. 225. 
Hydaticus austriacus and cinereus. Buddeberg, ojj. cit. pp. 423 & 424, 
notes the occurrence together of the first of these and a middle form 
between zonatus and cinereus, and gives sexual and other characters. 
Cybister japonicus, p. 45, lewisianus, p. 46, spp. nn., Japan, D. Sharp, I. c. 
Hydaticus jap)onicus, sp. n., id. I. c. p. 48, Japan. 
Gyrinid.^. 
Dineutes subspinosus, King (?), recorded from Syria and Palestine ; 
Leprieur, Bull. Soc. Ent. Fr. (5) iii. p. cxxvii. 
Orectochilus schistazeus, Gerst., figured ; V. d. Decken's Reisen, iii. pt. 2, 
pi. V. fig. 8. 
Gyrinus japonicus, sp. n., D. Sharp, I. c. p. 55, Japan. 
Dineutes marginatus, id. c. p. 56, Japan, Mantchuria, D. truncatus, id. 
Ent. M. M. x. p. 54, Chontales : spp. nn. 
Hydrophilid^. 
Hydrochares Jlavipes, Stev., and Laccobius minutus, L., occur (with 
slight modifications) in Japan ; and the structure of the abdomen of 
Amphiops is described : D. Sharp, Tr. E. Soc. 1873, p. 59, et seq. 
G. H. Horn, P. Am. Phil. Soc. xiii. pp. 118-137, gives "a revision of 
the genera and species of the tribe Hydrobiini'" found in the United 
