1883.] 319 [Hyatt. 



no annular lobes on the dorsum. The septa are concave as in 

 the Nautilini in the larvae, but become convex internally after 

 the rise of the magnosellarian saddles. The magnosellarian sad- 

 dles, besides their prevalence in the Devonian species and in the 

 larvae of later forms, are notable as resembling the similar large 

 saddles of some of the Nautiloids, as in the young of Enclimato- 

 ceras, and the rise of the septa dorsally in some of the Anarcestes 

 group. 



Parodiceras, 1 nobis, includes species with whorls in section 

 semilunar, sutures with very broad, generally flattened, and j)rimi- 

 tive forms of the first pair of saddles, lateral lobes shallow and 

 mostly angular, the magnosellarian saddles, often rising, as in the 

 young of Tornoceras above the level of the first pair on the venter. 

 Our opportunities for study in this genus have been limited but 

 we have been able to see that some species have very small 

 annular lobes and others, as figured by Sandberger in Jahrb. d. 

 Nass. Ver. Naturk. above quoted, had probably no annular lobes. 

 These characteristics of the septa and the general aspect of the 

 adults are transitional from Anarcestes to Tornoceras. In Branc. 

 umbilicatum according to Sandberger's figure, in Jahrb. Nass. 

 Ver. Vol. 7, 1851, pi. 2, fig. 9, there are slight saddles on the dor- 

 sum corresponding to the first pair on the venter, while in biar- 

 cuatum and amblylobum there are none. The first named species 

 is directly transitional from Parodiceras to the genus Brancoceras. 



The young are stouter than in Torn, auris and they also inherit 

 the semilunar and involute whorls at early larval stages. 

 Parod. curvispina is discoidal and biarcuatum, planilobum, an- 

 gulatum are all more involute species figured by Sandb. Verst. 

 ISTass. pi. 10, but the last is laterally compressed. Parod. 

 amblylobum, ibid, pi. 10, fig. 8, and pi. 4, fig. 5, has a compressed 

 whorl in the later larval stages. Parod. oxycantha Sandb. pi. 10, 

 fig. 3, in some specimens shows a decided tendency to division of 

 the ventral saddles as in Maenoceras bifer. Parod. (Gon.) sub- 

 lineare Munst. Ueb. Clym. et Gon. pi. 4, fig. 5, according to Mun- 

 ster's figure is transitional to the simpler sutures of Parod. (Gon.) 

 undulosum, sublaevis, and globosum, sp. Munst. Ueber Clym. et 

 Gon. pi. 4. We have found but one species in this country, the 



1 UapoSvs, transition. 



