I B RARY OF THE U N IVE.R.5ITY Of ILLINOIS 59O.S FI V Return this book on or before the Latest Date stamped below. A charge is made on all overdue books. University of Illinois Library .. 1943 II M32 THE LIBRARY OF Iht OCT6-1939 UNIVERSITY OF ILLINOIS MB» -24 ZOOLOGICAL SERIES OF FIELD MUSEUM OF NATURAL HISTORY Volume 24 CHICAGO, SEPTEMBER 19, 1939 No. 6 BY KARL P. SCHMIDT CURATOR OF AMPHIBIANS AND REPTILES The Sewell Avery Expedition to British Guiana for Field Museum in 1938, under the leadership of Emmet R. Blake, penetrated to the Brazilian boundary in the Courantyne District to make zoological collections. While the principal object of the expedition was the collecting of birds and mammals, a small collection of reptiles, amphibians, and fishes was obtained. This material, contained in two gasoline tins, was happily recovered intact after the calamitous wreck of the expedition's boats, on the return trip, in the King William Rapids, some miles below King Frederick William IV Falls on the Courantyne River. The tins contained enough air, with the bouyancy of their box, to float them. The collection of reptiles and amphibians amounts to 160 specimens, including 111 frogs, 39 lizards, and 10 snakes. Among the snakes is a single coral snake which is evidently undescribed, notable for its brilliant coloration, even in the brilliantly colored genus Micrurus. It is pleasant to name such a well-marked new species for Mr. Sewell Avery, Trustee of Field Museum, whose support of the, Museum's research interests made possible its discovery.1 The diagram of the color pattern is the work of Mr. Martin Melody. UNIVERSITY OF ILLINOIS Micrurus averyi sp. nov. Type from Courantyne District, near the Brazilian border, at Latitude 1° 40' N. and Longitude 58° W. No. 30956 Field Museum of Natural History. Adult female. Collected September 22, 1938, by Emmet R. Blake. 1 Mr. Blake's collecting in British Guiana in 1937 likewise yielded a single coral snake which proved to be the distinctive and remarkable Leptomicrurus collaris, described in 1837. My discussion of this specimen (Schmidt, 1937) unfortunately omitted reference to a paper on the identical topic by Joseph C. Thompson (1913). While Thompson's conclusions anticipate mine in part, they do not alter my statement of the history of the species. No. 448 45 46 FIELD MUSEUM OF NATURAL HISTORY— ZOOLOGY, VOL. 24 Diagnosis. — A species of Micrurus with the rings not in triads, head almost entirely black, no nuchal ring, and with relatively few black rings. Allied, presumably, to M. corallinus, but distinguished by the absence of the nuchal black ring, the smaller number of nar- rower black rings, and the reduction of the yellow rings to spots. Description of type. — Head slightly wider than body, snout broad as seen from above, eyes small, somewhat upwardly directed. Head shields normal in arrangement; upper labials seven-seven; lower labials seven-seven; anterior and posterior chin shields about equal; preoculars one-one, postoculars two-two; temporals one-one, and one-two; ventrals 210; anal divided; caudals 34. Eleven black rings on the body, each bordered narrowly by yellow, and separated by extensive red zones; the black rings two dorsal scale lengths in width, and covering two ventrals; the red zones extending over 12 to 18 ventrals; scales in the red zones entirely without black spotting; yellow borders of the black zones about one- half ventral wide, dorsally frequently interrupted, so that they form interrupted series of spots; the head black to a point behind the tips of the parietals, including the third temporal on each side, the black extending obliquely forward to cross the tips of the second pair of chin shields; the black narrowly bordered with yellow behind the chin shields; an irregular spot of yellow on each anterior chin shield; a yellow spot on labials 5 and 4, reduced to a trace on labials 3 and 2; red rings on tail narrower than the black, almost entirely obscured by black pigment, their position clearly defined by the sharply marked narrow yellow border. Measurements of type. — Total length 670, tail 58. Remarks. — The type locality may be further defined as the Boundary Commission's "Boundary Camp," at about 2,000 feet above sea level, at head of Itabu Creek. This creek enters the New River, an affluent of the Courantyne, at New River Depot. The status and relations of the present form must remain some- what obscure until male specimens are available for study. I have elsewhere shown (Schmidt, 1936) that the species Micrurus corallinus of authors is an omnium gatherum of forms, some of which are sharply distinguished from true corallinus of eastern Brazil by the presence of supra-anal tubercles in males. The relations of averyi may be with corallinus, from which it is distinguished by its small number of black rings and absence of a nuchal ring, and with orna- tissimus, which has the yellow rings similarly reduced to spots, but which is otherwise radically different in color pattern. 1939 A NEW CORAL SNAKE— SCHMIDT 47 The true coral snakes (i.e. the members of the family Elapidae, all venomous) now known from British Guiana are the following: Leptomicrurus collaris Schlegel Micrurus averyi sp. nov. Micrurus psyches Daudin Micrurus lemniscatus Linnaeus Micrurus surinamensis Cuvier Micrurus hemprichii Jan FIG. 5. Color pattern of type of Micrurus averyi sp. nov. Red shown in stipple. REFERENCES SCHMIDT, K. P. 1936. Preliminary account of coral snakes of South America. Field Mus. Nat. Hist., Zool. Ser., 20, pp. 189-203. 1937. The history of Elaps collaris Schlegel 1837-1937. Field Mus. Nat. Hist., Zool. Ser., 20, pp. 361-364. THOMPSON, J. C. 1913. The correct status of Elaps collaris Schlegel. Notes Leyden Mus., 35, pp. 171-175. UNIVERSITY OF ILLINOIS-URBANA