2 8 PAPERS FROM TORTUGAS LABORATORY vol. xxxiv 



chiefly by its long, low, broad head, depressed peduncle with a broad, dark keel, 

 and short dorsal and anal. Its nearest relative according to Breder is ardeola, 

 which apparently is timucu as identified by Longley. 



Breder discussed and illustrated in part the development of the young. 



Known only from Tortugas, Florida. S. F. H. 



Strongylura timucu (Walbaum) 



Common at Tortugas, as many as 63, 225 to 350 mm. long, having been taken 

 at one time. 



Dr. Longley 's notes, which are embodied in this account, are all under Tylo- 

 surus marinus. In his copy of Jordan, Evermann, and Clark's Chec\ list, how- 

 ever, he indicated that he had come to the conclusion that the specimens he had 

 earlier identified as marinus were timucu. Two specimens available for examina- 

 tion certainly are not Strongylura marina. On the basis of these data marina 

 apparently does not occur at Tortugas. It seems significant that marina was not 

 listed (field notes) from Key West during several years' intermittent collecting 

 by Bureau of Fisheries investigators, whereas timucu seemingly was rather 

 common. 



The 2 specimens from Tortugas examined by me have 14 and 15 rays in the 

 dorsal and 14 and 16 in the anal, and the scales on the single specimen retaining 

 them number about 255 in the lateral series, 24 series under base of dorsal, and 

 42 from origin of anal to base of caudal. In each specimen scales plainly are 

 present on cheeks and opercles. Dr. Longley has the following fin-ray counts, 

 based on 4 specimens: D. 12, 13, 13, and 14; A. 14, 15, 18, and 18. 



Strongylura timucu, according to the two specimens at hand, differs from 

 S. marina principally in having larger scales {marina having about 325 in a 

 lateral series, 38 under base of dorsal, and 66 from origin of anal to base of 

 caudal), which are present on both cheek and opercle (missing on opercle in 

 marina}. Furthermore, the ventral fins apparently are inserted farther back, 

 being more than twice as far from base of pectorals as from origin of anal, 

 whereas in marina they generally are exactly twice as far from base of pectorals 

 as from origin of anal. 



Dr. Longley stated : "This is by far the slightest of the three Tortugas species 

 recognized. The dermal keels on the sides of the caudal peduncle render the 

 body, of the young at least, of more nearly uniform width throughout their 

 length than the others. There is no marked inequality in the development of the 

 lobes of the caudal as in raphidoma." In another entry he said that these two 

 species may be distinguished readily in the water by the difference in the shape 

 of the body and tail. Furthermore, timucu has a longer and thinner bill, and no 

 spots on the sides, which sometimes are present in raphidoma. 



According to Breder (Carnegie Inst. Wash. Pub. 435, 1932, p. 7), the speci- 

 mens from Tortugas, examined by me, probably are S. ardeola. As understood 

 by Breder, timucu, which he also listed from Tortugas, has a longer dorsal fin 

 (17 rays) and a lower, wider head, the width exceeding the depth, whereas in 

 ardeola the depth exceeds the width. Breder stated also that the specimens listed 



