. Bulletin. Natural history; Natuurlijke historie. Fig. 25. Skull of .S'. tenuiceps. Camera lucida drawing of neolype, YPM 8162; Sunderland, Mas- sachusetts. Scale = 1 cm. Abbreviations; br, branchiostegal rays; d, dentary; ce, ceratohyal; cl, cleithrum; dpt, dermopterotic; dsp, dermosphenotic; ect, ectopterygoid; ex, extrascapular; fr, frontal; io, infraor- bitals; iop, interopercular; mpt, metapterygoid; op, opercular; p, parasphenoid; par, parietal; pmx, premaxilla; pop, preopercular; pt, posttemporal; q, quadrate; sub, suborbital. first dorsally, then posteriorly. Again, the posteriormost
. Bulletin. Natural history; Natuurlijke historie. Fig. 25. Skull of .S'. tenuiceps. Camera lucida drawing of neolype, YPM 8162; Sunderland, Mas- sachusetts. Scale = 1 cm. Abbreviations; br, branchiostegal rays; d, dentary; ce, ceratohyal; cl, cleithrum; dpt, dermopterotic; dsp, dermosphenotic; ect, ectopterygoid; ex, extrascapular; fr, frontal; io, infraor- bitals; iop, interopercular; mpt, metapterygoid; op, opercular; p, parasphenoid; par, parietal; pmx, premaxilla; pop, preopercular; pt, posttemporal; q, quadrate; sub, suborbital. first dorsally, then posteriorly. Again, the posteriormost scales have flatter bases and longer spines, each one overlapping the scale behind. Skull The pattern of dermal bones in the skull of the S. tenuiceps group shows little deviation from the general pattern described for the S. elegans group (Olsen and McCune ms), and for Semionotus (Schaeflfer and Dunkle 1950); it is described only briefly here. Skulls from individuals of two different species of the group, S. tenuiceps (Fig. 25), with robust dorsal ridge scales, and Semionotus saginatus (Fig. 26), with globular dorsal ridge scales, are figured here. The skull roof shows the only deviation from the general Newark semionotid pattern. The parietals are rectangular, almost square, and join medially. The frontals are narrow anteriorly in the S. tenuiceps group (Olsen and McCune ms), and the S. bergeri group including .S". (Lepidotes) minor (Woodward 1916-19; McCune 1986), and Semionotus normanniae (Larsonneur 1964). This contrasts to the broad frontals found in Semionotus braunii (Olsen and others 1982), Lep- idotes elvensis (Deschaseaux 1943; Wenz 1967), L. mantelli (Woodward 1916- 19) and L. laevi (MNHP 1917-05). In the S. tenuiceps group, the suture between the frontals is digitate as in the S. elegans group, but between the frontals and parietals the suture is almost straight rather than digitate as in the S. elegans. Please note that these images are extracted from scanned
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Keywords: ., bookcentury1900, bookcollectionbiodiv, booksubjectnaturalhistory
