Tai'iikospi'ys sulcatus, Leidy. 



Coiic, 1. c, \t. 104. — riataniju mtlcuUin, Lciily, Proccciliiigs of llju Aciiikiiiy ul' Pliil;uU'liilji;i, 

 1650, oUL! ; Crctaceoiu^ Koi>til('S ol'tlic Uiiitcil States, lbG5, lOll, Platu XIX, 11;;. 4. 



Grucusand of No. 5, New Jersey. 

 Tapiiuospuys leslianus, Cope. 



Extinct Batracliia auil Itcptilia of North Amurica, lb70, \i. KiG. 



Grcensaiul of No. 5, New Jersey. 

 TApiiKoypiiYS STEENUUS, Cope. 



Extinct BatracUia aud Ucptilia of North America, 100 1!, Itf/l). 



Gieeusar.d, No. 6, of New Jersey. 

 TaPUKO.'^J'IIYS nodosus, Cope. 



L. c, p. IGG C, Plate I, li-;. IG. 



Greeiisaiid below No. 5, New Jersey. 



PYTIIONOMOIIPIIA. 



Tlie (juadratc bones of the species of this order are represented in Plate 

 XXXVII In coinpletit)n of tlie description of this portion of the skeleton, I 

 wonld point out the coincidence l)etWeen the forms of tiie cpiadratc bone and 

 other characters employed in the preceding pages, as indicative of generic 

 divisions. To the ridges already described, I wonld add that the "mcatal 

 Iviiob" o? Mosasaurus is represented Ijy a ridge or crest in Liodon, and by one 

 less marked in Clidasfes ; and hence the term "knob-ridge" may be added. 

 The lower part of the great anterior ala turns Ijackward, and is generally 

 continued upward on the outer and anterior side of the knob-ridge ; this may 

 be called the "posterior alar" ridge. We then have : proximalli/, the alar pro- 

 cess : the internal angle; aud the internal longitudinal ridge; distuUij, Ijegin- 

 ning in front, the posterior alar ridge; the knob or knob-ridge; median 

 posterior ridge ; and the distal longitudinal ridge. 



Mosamu?-us differs from all the other genera in the absence of the inter- 

 nal longitudinal ridge. No other genus is known to ])ossess the median pos- 

 terior ridge, nor is the knob of the same form in any other. M. fulcidtus is 

 the only species of the ordiu- in which all four of the distal ridges are pnjsent. 

 In M. 7naximus, the knob is wanting; and in J/, giganlcus, the median poste- 

 rior ridge is not found. 



