584 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 83 



strikinglj^ in its larger size and also in having more numerous dorsal 

 and pectoral rays. 



Material studied. — Fox Bay, Colon, Panama; Meek and Hilde- 

 brand; March 25, 1911 (81727); one specimen mthout any brood 



pouch. 



Jamsus, new subgenus 



Genotype. — Hippocampus regulus Ginsburg. 



Definition. — Dorsal rays 10 to 14. Pectoral rays 10 to 12. Trunk 

 segments usually 10, often 9, infrequently 11. Caudal segments 28 

 to 34. Upper ridges of tail and trunk usually overlapping on one 

 segment, sometimes on two, rarely on none; usually on last trunk 

 segment, often on first caudal. First caudal segment usually quad- 

 rangular; last trunk segment usually octangular (last trunk and first 

 caudal segments often both hexangular in zosterae, in those specimens 

 having nine trunk segments, see p. 590). Penultimate trunk segment, 

 like the segments in front of it, usually septangular, infrequently 

 novemangular. Base of dorsal on two segments, usually on last 

 two trunk segments, often on last trunk and first caudal segments. 

 Size notably small. 



Relationships. — Jamsus is evidently related to the typical subgenus 

 but differs from it chiefly in having fewer fin rays, fewer trunk and 

 caudal segments, and normally one instead of two extra plates for 

 the support of the dorsal. In the number of dorsal and pectoral rays 

 there are no intergradients between the two subgenera in the species 

 studied. Jamsus contains two species, which are notably small in 

 size, and their smaller size is correlated with a lesser number of fin 

 rays and segments. 



Etymology. — An arbitrary combination of two Biblical Hebrew 

 words: jam ^°=sea, and sus ^°=horse, nouns in masculine gender 

 according to the rules of Hebrew grammar; transliterated into the Latin 

 alphabet according to the rules of the Library of Congress,^^ except 

 that the Hebrew letter "yod" is rendered into "j", equivalent to the 

 old Latin consonantal "i"; the "j" pronounced like the English "y-"' 



HIPPOCAMPUS REGULUS Ginsburg 



Figures 70, 71 



Hippocampus regulus Ginsburg, Journ. Washington Acad. Sci., vol. 23, p. 563 

 1933 (Mississippi; Texas; Campeche, Mexico). 



Diagnosis. — First caudal segment nearly always quadrangular (in- 

 completely hexangular in one out of 24 specimens examined), last 

 trunk segment always octangular, penultimate trunk segment nearly 



'" See, for instance, Exodus 15:1. 



•' See also Funk & Wagn alls Jowisb Encyclopaedia, vol. 2, p. ix. 



