402 BULLETIN 58, UNITED STATES NATIONAL MUSEUM. 



c' Snout, from oyo 1o 1i]) Hhortor than width of liead at posterior corner of supra- 

 oculars. 



(/' Mental not concealed in a deep groove [Lapemis], p. 435. 



cP Mental concealed in a deep groove of the chin [Enhydrina], p. 437. 



c- Snout, from eye to tip equaling or longer than width of head at posterior corner 

 of supraoculars Hydrus, p. 438. 



Genus LATICAUDA" Laurenti. 



1768. Laticauda Laurenti, Syn. Rept., p. 109 (type, L. scutata). 



1802. Platurus Latreille, Hist. Nat. Rept. IV, p. 183 (type, P. fasciutus). 



Five species of this genus are provisionally recognized, oi which 

 Laticauda muelleri'' seems to be a L. laticaudata with a ventral keel. 

 A Laticauda frontalis^ has recently been described as differing from 

 L. semifasciata in having an undivided rostral and shield-like tem- 

 porals. 



Only two species are known with certainty to have been taken on 

 the coasts of the territory covered by this work, but a third may be 

 reasonably expected to occur and its characters are therefore given 

 in conjunction with the others. They may be distinguished by the 

 following : 



KEY TO THE SPECIES OF LATICAUDA IN JAPANESE AND CHINESE SEAS. 



a^ Rostral undivided horizontally; belly without a median keel; two i)airs of contig- 

 uous chin-shields; temporals 1-f 2; top of snout yellow. 

 6' Scale rows 19; no unpaired shield between the prefrontals; upper lip dark l^rown. 



L. laticaudata. yt. 402. 

 b- Scale rows 21 to 25; normally an unpaircnl shield between the prefrontals: upper 



lip yellow [L. colvbrina, p. 406.] 



a^ Rostral divided horizontally; belly with a median keel on posterior half; one pair 

 of contiguous chin-shields; temporals 2+3; top of snout dark brown. 



L. semifasciata, p. 409. 



LATICAUDA LATICAUDATA rf (Linnaeus). 



1758. ( 'oluhcr laticaudatus Linn.eus, Syst. Nat., 10 ed., I, p. 222 (part: type-local- 

 ity, thelndies; tjpv in Mus. Stockholm) ; 12 ed. , 1, 1766, p. 383. — Anders- 

 son, Bihang Svensk. Vet. Akad. Handl., XXIV, 1899, Pt. 4, no. 6, p. 18 

 (tyj)e). — Platurus laticaudatus Girard, Herpet. U. S. Expl. Exjied., 1858, 

 p. 180 (Fiji Is.).— Peters, Mon. Ber. Berlin Akad. Wiss., 1877, p. 417 

 (part: Fiji, Tonga, Philippine Is.). — Boulenger, Cat. Sn. Brit. Mus., Ill, 

 1896, p. 307 (Bay of Bengal to western Pacific; Loo Choo Islands). — 

 Wall, Proc. Zool. Soc. London, 1903, i)p. 96, 101 (Formosa; Loo Choo 

 Islands); 1905, II, p. 517 (Okinawa). 



1768. Laticauda scutata Laurenti, Syn. Rept., p. 109 (substitute name for C. lati- 

 caudatus Linnaeus). 



a From latus, broad; cauda, tail. 



t> Platurus muelleriBov-LKNaFM, Cat. Sn. Brit. Mus., Ill, 1896, p. 309 (South Pacific). 

 '■ Platurus frontalis De Vis. Ann. Queensland Mus., No. 6, 1905, p. 48 (New Guinea). 

 t^From latus, broad; caudatus, tailed. 



