306 



Lituites imdatus (pars) Hall 1847. Pal. N. York, vol. I, p. 52, pi. 13, fig. 



1 ; and pi. 13 bis, the only figure. 

 Lituites undatus {pa,ts) 'Emmons 1855. American Geology, Pt. II, p. 146, pi. 



5, fig. 14. 

 Trocholitcs undatus (pars) Hyatt 1883. Proc. Boston Soc. Nat. Hist., vol. XXII, 



p. 267. 

 Eurystomites undatum, Hyatt 1894. Proc. Amer. Philos. Soc., vol. XXXII, 



p. 445. 



The type of this species, as now restricted, is a specimen from the 

 Black River limestone at Watertown, N.Y., collected more than sixty 

 years ago by Dr. Crawe, of that city. This specimen is the original of 

 Emmions' larger figure of Inachus undatus in the report on the Geology 

 of the Second District of the State of New York ; and of Hall's represen- 

 tation of Lituites undatus on Plate 13, fig. 1, of the first volume of the 

 Palaeontology of the State of New York. It is about three inches and a 

 half in its maximum diameter, but is very imperfect anteriorly. Only 

 one side of this fossil is preserved, and all that the specimen shews is the 

 general shape of the shell and some of the coarser surface markings, but 

 there are no indications of the siphuncle. Another specimen from Water- 

 town, collected by Dr. Crawe, which is figured by Hall (op. cit., pi. 13 his) 

 is fully six inches in its maximum diameter, though part of the body 

 chamber is broken off. It also gives no information as to the shape or 

 relative position of the siphuncle. Both of these specimens are in the 

 American Museum of Natural History at New York City. 



It is still doubtful to which genus of Cephalopoda this species should 

 be referred. Inachus was long ago rejected for it, as being preoccupied 

 in Crustacea and for other reasons. It is equally clear that it is not a 

 Lituites, and that it does not even belong to the family Lituitidse. Hyatt 

 regarded it as a Trocholites in 1883, but ultimately abandoned this view 

 and placed it in Eurystomites in 1894. On Plate 5, figs. 1 and 2, of the 

 " Phylogeny of an Acquired Characteristic,'' a small specimen from Po- 

 land, Herkimer County, State of New York, is figured under the name 

 Eurystomites undatus. This specimen, which is in the Walcott collection 

 in the Museum of Comparative Zoology at Cambridge, Mass., has been 

 kindly lent to the writer by Mr. Samuel Henshaw. It is about forty- 

 three millimetres, or about an inch and three quarters, in its maximum 

 diameter. One whorl and a h^lf are preserved ; these are in close con- 

 tact, widely elliptical in cross section, and wider laterally than in a dor- 

 soventral direction. On the earlier half of the outer whorl the test is 

 marked with numerous, close-set and minute, transverse raised lines, 

 which are straight in passing over the venter. But on the latter half of 

 this volution, the lines of growth are curved convexly on each side, and 

 concavely backward on the venter. The sutural lines are nowhere ex- 



