FISHERY BULLETIN: VOL. 75, NO 4 



in both the cephalic lateral-line system and the 

 anterior part of the lateral line, and the lips of both 

 jaws expanded (Soldatov 1922; Schmidt 1936; 

 Shmidt 1950). 



It is possible that the similarities described 

 above are not of real phyletic significance. A. P. 

 Andriyashev(pers. commun.) has pointed out that 

 the Hadropareinae and some other genera (e.g., 

 Zoarces) have vertebral centra with the anterior 

 cone shorter than the posterior cone, i.e., the con- 

 striction of each amphicoelous centrum is shifted 

 anteriorly. He adds that the Lycodinae, 

 Lycogramminae, and Lycodapodidae have "sym- 

 metrical" centra with the constriction placed 

 midway in the length of each centrum. The centra 

 in Exechodontes are symmetrical, indicating that 

 relationships may not be with the Hadropareinae 

 (see Figure 3). I have, however, examined radio- 

 graphs of Macrozoarces americanus andLycenche- 

 lys verrilli and find that both have "asymmetrical" 

 centra, at least anteriorly. Further analysis of ver- 

 tebral characters seem indicated. 



The following key should serve to separate the 

 four hadroparein genera. 



KEY TO THE HADROPAREINAE 



la. Cephalic lateral-line system without 

 pores; outer teeth of lower jaw placed 

 on anterior and lateral margins of 

 dentary and directed outward; scales 



and palatine teeth absent 



Exechodontes n. gen. 



lb. Pores of cephalic lateral-line system 

 present on upper parts of head; no out- 

 wardly directed teeth on lower jaw; 

 scales and palatine teeth present or 

 absent 2 



2a. Scales absent; musculature of cheek 

 enlarged, forming a prominent bulge 

 along margin of preopercle; palatine 

 teeth absent Hadropareia 



2b. Scales present; cheek musculature 

 may be slightly swollen, but not form- 

 ing a prominent bulge; palatine teeth 

 present or absent 3 



3a. Palatine teeth present; groove behind 



upper lip continuous across snout .... 



Davidijordania 



3b. Palatine teeth absent; groove behind 



upper lip interrupted at tip of snout. . 



Bilabria 



Discovery of a zoarcid in the Gulf of Mexico that 

 has its closest apparent affinities with a small 

 group of genera in the northwestern Pacific is of 

 zoogeographic interest. It is consistent with cur- 

 rent thoughts regarding the origin and relation- 

 ships of several faunal groups of the cooler North 

 Atlantic which also have affinities with the North 

 Pacific. The boreal North Pacific is considered a 

 dominant evolutionary center which provided 

 significant numbers of migrants that invaded the 

 Arctic and North Atlantic during the late Miocene 

 and late Pliocene epochs (Briggs 1974). 



Discovery of Exechodontes might suggest that 

 there are a number of undescribed species of the 

 family inhabiting the slope waters of the Ameri- 

 can warm-temperate and tropical Atlantic. The 

 only previously known zoarcid from the Gulf of 

 Mexico is Lycenchelys bullisi Cohen which ap- 

 pears to be related to species found in the northern 

 Atlantic and Gulf of Panama (Cohen 1964). 

 Otherwise, the southernmost record for the family 

 in the western North Atlantic is that of Lycodes 

 brunneus Fowler from off the east coast of Florida 

 just north of the Bahama Islands (Fowler 1944). In 

 the eastern Atlantic, the family is known south to 

 about lat. 20 °N, where two species, probably both 

 misidentified, have been captured at depths be- 

 tween 1,000 and 1,500 m (Vaillant 1888). The 

 pelagic species Melanostigma atlanticum has been 

 recorded southward only to the waters off Virginia 

 (McAllister and Rees 1964). It is significant in the 

 present context that M. atlanticum is most closely 

 related to the western North Pacific M . orientate 

 rather than the eastern North Pacific M. pam- 

 melas (Tominaga 1971). 



Name. — From the Greek exeches, projecting, and 

 odontos, teeth. The compound is a masculine 

 noun. 



Exechodontes daiduleus n.sp. 



Holotype. — 96.3 mm SL (standard length), col- 

 lected at Oregon II station 10632: 27°01'N, 

 84°55 ' W, about 120 n.mi. ESE of Tampa Bay, Fla., 

 in 503 m (275 fm); 124-ft shrimp trawl, dragged on 

 the bottom, 18 June 1969. The specimen (Figure 1) 

 has been deposited in the National Museum of 

 Natural History, Washington, D.C., USNM 

 211797. 



Description. — All measurements are given as 



790 



