64 Memoir Sears Foundation for Marine Research 



are hinged by a peg- and groove-type articulation. Although the bony scales form nearly 

 an impenetrable covering, the articulations, the fibrous connections, and the arrangement 

 in diagonal rows allow some flexibility of the body. The lepisosteid ganoid scale is com- 

 posed of two layers, ganoine above and isopedine below, both of which are irregularly 

 penetrated by vascular canals.* In addition, both layers, especially the latter, are per- 

 forated by a system of small tubes; these tubules penetrate the scale from all sides and 

 are dendritic at their inner terminations. A similar layer of ganoine is present on the 

 dermal bones about the head. Both margins of the caudal fin as well as the leading 

 margins of the other median and paired fins are fortified with a biserial row of fulcra. 

 The cheeks are covered by numerous irregular plates. 



The swim bladder,* cellular and highly vascularized, is connected to the pharynx 

 by the enlarged pneumatic duct (Wiedersheim, yo: i— 16, pis. 1—3). The gonads are 

 staggered (Miiller, 49: pi. 6, fig. 2), i.e. the right one is mostly anterior to the pelvic 

 fins and the left one mostly posterior to them. The ovaries are closed, and the right 

 and left oviducts join the respective urinary ducts. A short distance posterior to their 

 junction, a common chamber is formed by the union of right and left parts; thus 

 the products from both systems exit from the body through a single urinogenital 

 sinus. No vestigial Miillerian ducts exist in the male (Pfeiffer, ^2: 465). The conus 

 arteriosus is a contractile vessel with several rows of valves (^9: pi. 5, fig. 2). 

 Remnants of the spiral valve occur in the posterior part of the gut. There is no lumi- 

 nescent organ. 



Taxonomic Rank. In 1844, Johannes Miiller combined his family Lepidosteini 

 (evidently to include the amiids) with his family Polypterini to constitute his Order 

 Holostei (^9: 201—204), and they have been similarly ranked as one of the constituent 

 divisions of a more widely inclusive Order by some subsequent authors. Thus they were 

 associated: with the Amiidae and Polypteridae by Giinther {28: 328) and with the Amii- 

 dae (among living fishes) by Bridge {l2\ 495, 502) as the Order Holostei; with the 

 Amiidae (among living fishes) by Arambourg and Bertin {2^: 2 181— 2194) in 1958 as 

 the Order Amiiformes. 



They have been regarded, however, as the sole living representatives of a separate 

 Order by the majority of recent authors: Ginglymodi by Cope {16: 452, 453), Rhom- 

 boganoidea by Jordan and Evermann (57: 108), Lepidosteoidei by Goodrich (2J: 340), 

 Holostei by Jordan (j6 : 115), Ginglymodi by Regan {^^g : 313), Holostei by Jordan 

 et al. (j8: 2^)y Lepidosteiformes by Berg (8: 211, 414), Semionotoidea by Romer 

 (62: 580), Lepisosteida by Matsubara (^6: 170), and Ginglymodi by Norman (5X: 

 61). Here also they are regarded as representing a separate Order. 



Name of the Order. The choice here lies between Ginglymodi and some derivative 



3. For accounts'of the~scales, see especially L. Agassiz {2: 74, 75, 77, tab. G, figs. 8-io), Williamson (75: 435-447, 

 470, pi. 40, figs. I, 2; 74: 651, 658, 687, 699), Reissner (67: 254-268, pi. 5, figs. :-6), Nickerson {50: 115-139, 

 4 pis., 31 figs.), Scupin (6j: 166, 167, pi. 10, fig. i), Goodrich (2J, 758, 759, fig. 199; 43: 21S, 219, fig. 192), 

 Kerr {^40: 63-66, figs. 3, 4). 



4. Apparently the swim bladder functions as a breathing organ (Potter, $4: 63) in addition to the gills. When 

 removed from water, the Garfishes regularly breathe air into and out of the swim bladder. 



