1890.] HELODERMA SUSPECTUM. 235 



very close affinity with them. Giuither has said ^ that " Central 

 America possesses, besides, five other families, small in species and 

 restricted in range (some belonging to the fauna of great elevations), 

 but highly interesting types. These arc the Eublepharides, Xeno- 

 sauridce, Aniellidce, Helodermafidce, and Lepidophymatidce. Their 

 localization and differentiation can be accounted for on the hypothesis 

 that they are the remains of the fauna of the various islands into 

 which Ceutral America was broken up at a former period." This is 

 likewise quite in the line of my thinking. 



XVI. Bibliography. 



The following works are the principal ones that refer to the 

 llELODERMATID^E, and the most important of them have been 

 consulted by the writer in counectiou with tlie present monograph. 



(1) Itiol. Hkunandez (Franciscus). — ' Historise animalium et 



mineralium Novae Ilispanise liber vuicus ' ; Cap. p. 315. — 

 (This is the first authority that alludes to H. horridum, and 

 in the volume quoted we find a very fair description of the 

 lleptile, the author stating that it was known to the Mexicans 

 as the Acastelepon, but to the Spanish Creoles as the " Es- 

 corpion.") 



(2) 1829. WiEGMANN (Arend Fridericus Augustus). — Isis, 



pp. 627-629. — (Under the name of Trackyderma horridum, 

 \\ iegmann, in this place, presents us with rather a super- 

 ficial description of a Mexican specimen of the reptile ; see 

 also the same work, p. 624, //. horridum.) 



(3) 1830. Wagler (Joannes). — Natiirliches System der Am- 



phibien. P. 164. — (This naturalist places Heloderma among 

 tlie Thecoglossce jileui'odontes.) 



(4) 1833. Idem. — JDescriptiones et Icoues Amphibiorum. Fasc. 



2. — (An unpaged description, in Latin, illustrated by an in- 

 differently executed figure of Heloderma horridum, from an 

 alcoholic specimen wiiich had been brought to Berhn.) 



(5) 1833. ScHiNZ (Heinrich Rudolph). — Naturgeschichte und 



Abbildungen der Reptilien. Text and Atlas, 4to. Leipzig. 

 P. 95 ; tab. 33.- — (^Vagler's drawing accompanied by a no 

 better description in German.) 



(6) 1834. Wiegmann (Arend F. A.). — Herpetologia Mexicaua 



seu Descriptio Amphibiorum Novse Hispanite. Berolini. 

 Pp. 6, 7, and tab. i. — (Here this author's well-known 

 suborder of the Squamata is divided into three series, — the 

 Leptoglossi, the Rhyptoylossi, and the Pachyglossi. Of these 

 the Leptoglossi is again subdivided into the Brevilingues 

 and the Fissilingues, and in the last-mentioned group the 

 Heloderma has been placed, in a family created for it, the 

 Trachydermi. His coloured figure of Heloderma horridum 

 is too brown in its colouring, and in form only presents us 



^ EucyclopascUa Britauiiica, 9th ed. vol. xx. p. 470 (1886). 



