ORDER II AMMONOIDEA 583 
VII. MorpHOCcERATIDA. 
Some families resemble Dactylioida and have similar young, the only constant 
distinction being the presence of « smooth zone along the median plane of the venter. 
Other families very like Cosmoceratidae, but their coronate young and sometimes highly 
coronate adults appear to place them in this series, 
Family 18. Morphoceratidae.  Globose and usually involute forms with 
open umbilici showing young to he highly coronate until a late stage. Costae on um- 
hilical zones single and widely 
separated, but divide into very 
broad bundles of fine, closely- 
set ventro-lateral costae differ- 
ing from those of all other 
eroups except some Peri- 
sphinctidae. Only one line 
of tubercles or nodes, which 
usually oceur at umbilical 
shoulders. External and 
dorsal sutures resemble those 
of Perisphinctidae, but not so 
uniformly inclined  apicad. 
In discoidal coronate shells 
the lobes and saddles are of 
equal length, and dorsum has 
two pairs of zygous lobes and 
two pairs of saddles. 

Fig. 1219. 
Mo rph Oss Douv. } Reineeckia Brancoi, Steinm. Caracoles, Bolivia (after Steinmann). 
Garantiana, Siemirad. ; Olco- 
stephanus (Holcostephanus auct.), Neum. ; Polyptychites, Simbirskites, Astieria, Virgatites, 
Payl. and Lampl. Upper Jura and 
Cretaceous. 
Family 19. Reineckidae. 
Discoidal shells with costae single on 
the lateral zones but bifurcated on 
their outer parts, and with one or 
two lines of tubercles, the first being 
near the point of 
bifurcation of the 
costae, and the 
other near thei: 
ventral termini. 
Division of costae 
takes place along 
ventro-lateral 
angles and not on 
a or near the um- 
Eig. 1220. bilical shoulders. 
Parkinsonia Parkinsoni, Sowb. sp. Inferior Oolite; Bayeux, Costae cross the 
Calvados. 

Fic. 1221. 
. Ocecoptych ius refractus, 
venter only in the deHaansp. Callovian; 
. . : : ; ° ae . Niort, France (after 
coronate young, when section is trapezoidal as im Coeloceras. Qoypieny). ( 
Sutures as in preceding family. 
Reineckia (Fig. 1219), Parkinsonia (Fig. 1220), Bayle ; Occoptychius, Newn. (Fig. 
1221); Aulacostephanus, Sutner and Pomp.; (’) Waagenia, Neum., Strenoceras, ger 
noy. Type S. (Amm.) niortense, VOrb. sp. Middle and Upper Jura. 
= 
