Vol. I] VAN DEN BURGH—SNAKES OF THE GALAPAGOS ISLANDS 341 



labial streak just above. In the one exception, a young speci- 

 men, there are mere traces of the dark spots. 



The largest specimen measures 820 mm. from snout to vent, 

 and has a tail 253 mm. long. 



Habits. — Nothing is known of the breeding habits of any 

 of the Galapagos snakes. One of the Hood Island specimens 

 (No. 9306) contained the tail of a large Tropidurus which 

 it had eaten. 



General remarks. — Snakes still are abundant on Hood 

 Island. They seem to differ from those of Charles Island only 

 in coloration; but, since the differences are constant in the 

 large series at hand, they must be regarded as a distinct 

 species. 



The sexual difference in the number of scale rows in the 

 snakes of this one island is worthy of note. 



Dromicus dorsalis (Stsindachner). Galapagos Snake 



1869, Dromicus chamissonis Peters, Mon. Berlin. Acad., 1869, p. 719; 

 GiJNTHER, Zool. Record, 1869, p. 115 (part) ; Boulenger, Cat. Snakes Brit. 

 Mus., II, 1894, p. 119 (part). 



1876, Dromicus chamissonis var. dorsalis Steindachner, Festschr. 

 Zool.-bot. Ges. Wien, 1876, p. 306, pi. I, fig. 1 (type localitieslndefatigable 

 [probably] or Jervis islands). 



1876, Dromicus chamissonis var. Habelii Steindachner, Festschr. Zool.- 

 bot. Ges. Wien, 1876, p. 306, pi. I, fig. 1 (type localities Indefatigable 

 [probably] or Jervis islands). 



1889, Opheomorphus chamissonis Cope, Proc. U. S. Nat. Mus., XII, 

 1889, p.' 147. 



1892, Orophis biserialis Garman, Bull. Essex Inst., XXIV, 1892, p. 85 

 (part). 



1903, Dromicus biserialis biserialis Heller, Proc. Washington Acad. 

 Sci., V,'l903, p. 93 (part). 



Diagnosis.— Sca\e-^its present; scales in 19 rows; gastros- 

 teges 213 to 236; urosteges 95 to 119, usually some unpaired; 

 postoculars two, rarely one; temporals usually 1+2 or 1+1; 

 usually striped, sometimes spotted (on Barrington and Inde- 

 fatigable). 



Types.— Vienna IMuseum. Galapagos Archipelago, prob- 

 ably Indefatigable (or Jervis). Dr. Habel. 1868. 



