1883.] 335 ' [Hyatt. 



equals Sag. Haiclingeri, Gabb. Geol. Calif. Pal. Vol. 1, pi. 5, fig. 8-10. 

 This genus is separable from Medlicottia by the flattened outlines 

 of the first pair of saddles, and from Beloceras by its divided 

 lateral lobes. We do not feel sure that the ventral lobes are 

 undivided, though here as in Beloceras the generation of the 

 auxiliary lobes and saddles on the venter is similar to the same 

 process in Maeneceras, which takes place in the outlines of the 

 first pair of saddles. These saddles and the sutures generally are 

 similar to Beloceras. while the form of the whorl and abdomen 

 show close afiinity for Medlicottia. 



Lobites, Mojsisovics, Das. Gebir. um Hallst. pt. 1, p. 155 and 

 Med. Trias. Prov. p. 176 are apparently distorted or retrograde 

 forms with sutures similar to those of this family. Whether they 

 are really members of this family and can be traced to an origin 

 in genera like Popanoceras or Sageceras or some allied groups, we 

 have no proper means of ascertaining. Mojsisovics regards them 

 as genetically connected with Maeneceras delphinum in which the 

 living chamber is similar, having a contracted shape which appears 

 at first sight to justify this opinion. We, however, can regard 

 such resemblances as genetically important only when species are 

 similar in the sutures, and also found in closer relations in time. 



[Prolecanites.] 



Prolecanites, Mojsisovics, Med. Trias. Prov. p. 199, includes 

 species with more or less discoidal forms, smooth, compressed 

 whorls and a variable number of lobes and saddles. The ventral 

 lobes are undivided. The lobes are hastate and the saddles club- 

 shaped. The first pair of saddles become divided to form an 

 additional pair of lobes and saddles and the auxilliary lobes and 

 saddles are formed by division of the magnosellarian saddles. 

 According to this author the type is Prol. (Gon.) mixolobum, sp. 

 Sandb. Verst. Nass. pi. 3, fig. 13, not pi. 9, fig. 6, which is a Pro- 

 norites. Besides the species enumerated by Mojsisovics we 

 include in the same genus also Prol. (Gon.) lunulicosta, sp. 

 Sandb. ibid., pi. 3, fig. 14 with five pairs of lateral lobes and 

 saddles. As we have remarked above on p. 333, Sandb. Chemun- 

 gense, sp. Hall, Nat. Hist., N". Y., Vol 5, pt. 2, pi. 69, makes a 

 very near approach to this genus. 1 



1 Lecanites, Mojsisovics, Mediter. Trias. Prov. p. 200. which has for its type Lee. 

 glaucus, ibid. pi. 30, is described by the author as genetically connected with Pro- 



