222 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



species have two ethmoidal pores at tip of snout. The second eth- 

 moidal pore is fused with the first supraorbital pore to form a single 

 exterior pore (e^ S^). Generally two supraorbital pores occur on the 

 snout, (S\ S^) ; however, only four are present in triporiceps (S^, S^, 

 S^, S^). There are 9 to 11 preoperculo-mandibular pores present: 

 cinereus has 10 (11th missing), triporiceps has 11, orbignyanus has 

 9 or 10, and all others have 9 (pm^, pm" missing). There is generally 

 one supratemporal pore (st) in the genus, but only triporiceps has 

 three. The range of variation interspecifically for the lateral line 

 pores on the body is from 35 to 47; the fewest numbers are found in 

 esculentus, oligoporus and macrocephalus and the greatest numbers in 

 orbignyanus and conger (table 2) . In addition to these sensory pores, 

 surface sensory organs (x), which are in series, also are developed. 



In myriaster these sensory pores and organs are accentuated by a 

 light area surrounding them. Usually this character is important to 

 distinguish this species, but in some old specimens these light areas 

 are not discernible, thus making identifications difficult. See remarks 

 under the species myriaster for further discussion. 



Preorbital bone: The shape of the preorbital bone in Conger is 

 significantly different than those of other genera in the family. It 

 is a flat triangular bone, the longest side presented ventrally with a 

 groove at the lower side. The dorsal apex is generally presented 

 toward one side; but in myriaster it is more toward the middle than 

 in other species (pi. 1,a). Conger cinereus (pi. l,i) shows the greatest 

 ossification, whereas myriaster shows the least. More ossification 

 develops with increased age. In adult triporiceps, wilsoni, and jordani 

 this ossification has bridged over the sensory groove, but in young 

 jordani this ossification has not developed. In erebennus and myriaster 

 this groove is not bridged over by bone even in the largest specimens. 

 Tough connective tissues bridge over this groove in all species, but 

 these tissues were removed to show the underlying ossification. 



Dentition: The number of rows of teeth, the number of com- 

 pressed teeth, and the shape of the vomerine tooth-patcli are of 

 importance in distinguishing some species of Conger. One or two 

 rows of teeth occur laterally on the jaws. The outer row is compressed 

 to form a cutting edge. In those species with a single row of teeth, 

 two or three teeth may be found where the inner row would be ex- 

 pected. The inner row in those species with two rows of teeth varies 

 from a few teeth anteriorly in young specimens to almost a complete 

 row in the larger specimens. The number of teeth in the jaws increases 

 directly with age (table 4 and fig. 2). The greatest numbers are found 

 in triporiceps. The vomerine tooth-patch is generally triangular in 

 shape; however, in small triporiceps this patch is a single irregular 

 row and becomes triangular in shape in larger specimens. 



