Tlerpetohgical Fauna of Mount Kina Baloo. 343 



and both Dr. Mocquard and myself received Dr. de Jeude's 

 separate copy containing the description of Lepidognathus 

 towards tlie end of the same month. It is therefore impossible 

 for me to decide which description has priority, although I 

 incline to believe it is Dr. Mocquard's ; on the other hand, the 

 name Helicopsoides is so defectively constructed that I for 

 one would not hesitate to employ the name Lepidognathus if 

 the genus should stand. But it is my opinion that both 

 genera, togetlier with ray Calamohydrus, should be united 

 with Giinther's Opisthotropis, founded upon a West-African 

 species, and which may be defined as follows : — 



Opisthoteopis. 



Opisthotropis, Giinth. Ann. & Mag. Nat. Hist. (4) ix. 1872, p. 16. 

 Calnmohijdrus, Bouleng. Ann. & Mag, Nat. Hist.' (6) ii. 1888, p. 43. 

 Helicopsoides, Mocq. Le Natur. xii. 1890, p. 154. 

 Lepido(/}iaf7tus, Jeude, in M. Weber, Zool. Ergebn. ii. p, 186 (1890). 



Maxillary teeth small, equal, 20 to 25 ; mandibular teeth 

 small, equal. Head small, not distinct from neck ; eye 

 small, with round pupil ; nostril directed upwards, in a divided 

 or semidivided nasal. Body cylindrical ; scales finely striated 

 and keeled, without apical pits, in seventeen or nineteen rows 

 Tail moderate ; subcaudals in two rows. 



Four species are known, distinguished as follows : — 



A. Scales in 17 rows ; nasals separatpcl 



by the interuasals. 



Praefrontal single ; 8 upper labials, 

 fifth entering the eye 1. O. atra, Gthr. ( W. Africa). 



Prsefrontal single ; 8 upper labials, 

 none entering the eye 2. 0.^«<Zer«'o«u,Blgr.( Hong Kong). 



Two prtefrontals ; 12 upper labials, 

 none entering the eye .3. O. rugosa, Jeude (Sumatra). 



B. Scales in 19 rows ; nasah in con- 



tact behind the rostral 4. O. ti/pica, Mocq, (Borneo). 



3. Ablabes jyeriopSf y ar. prceJrontaliSj Mocq. 



This form is undoubtedly specifically distinct from A. 

 periops, Gthr. ; the two species constitute in my opinion a 

 new genus, which I propose to call 



Hydrablabes, gen. nov. 



Maxillary teeth small, equal, about 18 ; mandibular teeth 

 small, equal. Head small, not distinct from neck ; eye 



24* 



