Fishes of the Western North Atlantic 149 



lower jaw. Gill rakers present in all. Proethmoids not paired. Sides of snout without 

 Sensory canal-bearing bonelets. Branchiostegal rays slender, rod-like, not forming 

 part of the opercular system. Teeth, if any,^ small in most, larger in a few (Chirocen- 

 tridae); dental patterns various; teeth never present on the parasphenoid bone in mid- 

 line of roof of mouth rearward. Premaxillaries not protractile, except in some Alep- 

 ocephalidae and in the Phractolaemidae.* Maxillaries forming part of upper bor- 

 der of mouth in the great majority. ^ Lower jaw without predentary or supra-angular 

 bones. Temporal foramina present. « Basal radialia of the pectoral fin in one row 

 in most, articulating directly with the pectoral girdle; in two rows in a few (among 

 the Chirocentridae, 11: 9-1 1, fig. 23; i: 227, fig. 118, 424). Pectoral girdle with 

 a mesocoracoid element. Pelvic girdle not connected to the pectoral girdle. Last 

 few Vertebrae not evidently upturned in any; lateral processes bearing pleural ribs 

 (parapophyses) simply wedged into pits in vertebral centra, not fused with the lat- 

 ter; a lower series of intermuscular bones well developed in many (notably among 

 Clupeidae), connected basally to pleural ribs and lying between muscle blocks (myo- 

 tomes).' Ovaries with complete Oviducts, so far as known. Swim bladder present in 

 most,* dorsal in position, and connected throughout life to the alimentary tract via 

 an open pneumatic duct. Stomach with numerous pyloric caeca. Intestine without 

 spiral or circular folds in most, but perhaps not in all.' Arterial cone of heart 

 never with two rows of valves. Larvae not leptocephalus-like. 



Families. The following families fall within the Suborder as defined above: i 

 Clupeidae, including Dussumierinae and Dorosomatinae, p. 257; 11 Alepocephalidae, 

 p. 250; III Searsiidae, p. 254; iv Engraulidae, p. 152; v Chirocentridae (regarded by 

 Regan \8: 313-314] and Norman [5: 72] as a subfamily of Clupeidae; by Berg 

 [j: 227, 422] as a separate Suborder, Chirocentroidei), Indian Ocean, China, and 

 Japan; VI Chanidae, tropical Indo-Pacific; vii Phractolaemidae, Niger and Congo rivers; 

 VIII Kneridae, rivers of tropical Africa; and ix Cromeriidae, the Nile. 



Clupeidae, Alepocephalidae, Searsiidae, and Engraulidae are represented in the 

 North Atlantic. The Dolichopterygidae and the Macristiidae have also been referred 

 to the Clupeoidea by one author or another. But Dolichopteryx (Part 4) falls among the 

 Argentinoidea, as has long been evident from Parr's excellent illustration of it (6: 37, 

 fig. 14). And the affinities of the Macristiidae remain as doubtful today as was the 

 case in 191 1, when Regan (7: 204, 205) redescribed the only specimen of the family 

 that has yet been seen. 



The Chanidae lack teeth, at least as adults. 

 A freshwater family. 



In Nematalosa the mouth is bordered above by the premaxillaries, with the maxillaries covered by the lip, as is 

 pictured very clearly by Ridewood (9: 465, fig. 127 as "Chaetoessus"). 

 Shown clearly in Ridewood 's illustrations; see ftn. 5. 



For a diagram showing the relative positions of the pleural ribs and of the lower intermuscular bones, see Ber- 

 lin {4: 704, fig- 462). 



Lacking among the Alepocephalidae; probably among the Searsiidae also. 



A structure suggesting the elasmobranch spiral valve, but probably not homologous, has been reported 

 in Chirocentrus (see especially Goodrich, 3: 116, fig. 77) and in Alepocephalus (Cuvier and Valenciennes, 

 2: 176). 



