2'6i) lUJLLEllN ;JI, UiNlTKD STATKS NATIONAL MUSEUM. 



i'Si:ui)onnAN'ciirs (imy. 



All" I'liilos., l-i'J."), l>. •■iW; Cut. Hatr. Uiad. liiit. Miis.,()l»; Boulcnj,'er, 

 ( at. Miitr. ISrit. Mus., cil. ii, H--,', p. W/. 



Digits rliive. Jaws wi Ii Iioni.v slu'iitli. Tongue froo in fnuit; eyes 

 distinct. Hxternal Inanciiiii' tlncc Parasi>!RMioi(l teeth in two rows, 

 united in fiont, forming a iongitndinid A- <^)"e brancliial llssuro on 

 each side. 



The reduced number of digits and of l>raiu;liial fissures are tlie char- 

 acters which sei»arate this genus from Siren. The jK'culiarities found 

 in the branchia' arc shared by tlie hitter genus, liiit one species of 

 Pseudobrauchus is luiowu. 



, .: 



PSIUJDOHKANCIIUS STRIATUS L.coiit.-. 



eiray, Aiii'- I'liilos., I-,'.'), i>.-Jli; ; (1 ray, Cat. 15a tr, (irail. IJril.Miis., ud. i, p. 

 (i'.t; Ji()iilonj;cr, Cat. I!:itr. (irail. Hiit. Mus., cd. ii, l^-^l, y. S7. 



Siirii Kliiiitd licconto Ann. l.yi., N. V., l&i\, \>. ;')•.', I'l. I; Tscliiidi, IWitr., i>. IW. 

 llolbi'., X. A. lliii>., V. 1), Mil, ri. iiii; 1)11111. iV r.iln-., IM. W, W'^. 1. 



Tliis s[)ccies is iiuicli smaller than the >Sircn hurrl'uw, and dilfers from 

 it in a good many characters. The body iscylindric, and the tail meas- 

 ures two-thirds the lengtli of the head and body and a little more. The 

 liead viewed from above has a rather narrow oval outline, and its ex- 

 tremity is rounded without truncation, or sometimes acuminate. In 

 profile the front descends regularly to the end of the muzzle, which 

 overhangs the mouth ly a little. The ey«'s are <|uite (listin(!t, though 

 small, and are on the border of the head when \ ieweil from above, but 

 have moreui)ward than lateral <lir»'ction. Tlie mouth is veiy small and 

 does not extend so far posteriorly as the anterior border of the eye. 

 The upi»er lip is pendulous, <»verlappiiig the lower, so as to reduce the 

 mouth when closed to a small aperture on the middle line in front. 

 The !ip of the lower Jaw is not recurved, and there is no groovt^ pass- 

 ing around the chin. The external iio.^trils aie in the upper lip, not 

 very near its edge, but they are not visible from above. The distance 

 between them is three <|iiarters the length of that between the eyes. 



The parasphenoid series of teeth ai'c but little in contact in front, and 

 each one consists of two or thre(^ row.s. They extend anteriorly near 

 to the i)remaxillary and jiostericuly to oi)posite the rictus oris. The 

 choanal are round, and are at the external side of the parasphenoid 

 series, one-fifth the distance anterior to their posterior extremity. The 

 tongue is narrowed and acuminate in front, and its free portion is rela- 

 tively longer than in the Siren Idccrtind. 



The branchia' have not the .same character as those of the Hhrn laccr- 

 tina, being trii>innate on the external side only. The first is much 

 shorter than the seconil, which is shorter than the third. The single 

 lissure is below the ba.se of the second. I have not found a second 

 fissure in this species, nor have I found this one closed in individuals with 



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