NO. 6 MYERS AND WADE: NEW WEST COAST FISHES 183 



labial membrane and appear as small dermal points on the oral edge of 

 the upper lip. Partial dissection and careful examination of additional 

 genera of Congrids reveal several modifications of this structure, which 

 are described in this paper. 



Projecting bony processes are entirely absent in the genus Chiloconger 

 (Myers and Wade, 1941, p. 66), the inferior edge of the labial canal 

 being entirely unmodified. In Thyreoconger, a new genus described here, 

 the inferior edge of the labial canal is expanded into a broad shield or 

 winglike plate, which extends outward and downward to the oral edge 

 of the lip. The structure of the labial canal of a large (245 mm) speci- 

 men of Alloconger flavirostris (Stanford 21100), in the Natural History 

 Museum of Stanford University, is similar to that of Chiloconger, the 

 inferior edge of the canal being entirely unmodified. The genotype 

 (Stanford 6469) and three paratypes (Stanford 6969) of Rhynchocyinba 

 nystromi from Japan possess several bony processes extending downward 

 into the oral edge of the upper lip. A new species of the genus 

 Rhynchocymba, described here, has the same structure as the Japanese 

 species of the genus. 



The following key to the Congrids has been adapted from Reid ( 1934, 

 p. 3) and modified to include the genera Chiloconger, Alloconger, 

 Thyreoconger, and Rhynchocymba. It is entirely provisional in character 

 and subject to change with the accumulation of additional data. 



Provisional Key to the Genera of Congridae Discussed 



IN This Paper 

 la. Edge of upper lip turned upward into a free flange, either narrow 

 or broadly rounded ; bony projections from the inferior edge of the 

 labial canal either present or absent. 

 2a. Bony processes from inferior edge of labial canal present; 

 upturned labial flange narrow, with a free superior border; pre- 

 maxillary teeth not separated from vomerine teeth by a narrow 

 groove; snout longer than eye, not abruptly decurved . 



. Ariosoma Swainson 

 2b. Bony processes from inferior edge of labial canal absent. 



3a. Upturned labial flange expanded into a broadly rounded flap, 

 the highest part reaching or covering the posterior nostrils; 

 snout shorter than eye, abruptly decurved ; premaxillary teeth 

 separated from vomerine teeth by a narrow groove . 

 Chiloconger Myers and Wade 



