118 



1 had already believed to be as herein explained, and as stated by Prof. Huxley, though I had not boon able, as ho 

 has, to place the elements called by Owen clavicles in the position of Lschia, but rather of pubes. Prof. Huxley's 

 determination of the ilium of Megalosaurus, a point of the greatest importance, was new to me, and I have added 

 this and other allusions to his address. Other than these 1 have added nothing to the history oi Laelaps since its 

 original preparation beyond a few points in the restoration which grow only out of my original observations.* 



It is not however a, matter of surprise, that with the increased number of students at the present time, the same 

 subject should be under cotomporary investigation, and the same results be brought, out at the same time. 



LAELAPS MACROPUS, Cope. 



CodoMurua anti'/um, Part, Leidy Oetaceous reptiles, p. t 10 (Fragments of tibia, metatarsal bone and phalanges 

 from Monmouth county, X. J.) also p. 101. Lailaps aquilunguis, part, Cope, Proc. A. N. Sci., Phil., 1866, 279. 



The remains on which this species is based have, been described by Leidy 1. c. without distinct determination. 

 That, it, is distinct from the animal called by him Coelosaurus antiquus is very probable from the great difference in 

 size (it is double the latter in most, measurements), and from the greater expansion of the distal end of the tibia. 

 Width head to tibia, 3 in. to 4in.; in Coelosaurus antiquus 25 lin. to 31. lin. However, until some additional portions 

 of Coelosaurus are discovered, its character will remain unknown, and I prefer to associate the present with Laa- 

 Iaps until this is the case. The event may be that it pertains to neither genus. 



It differs from Laelaps aquilunguis in its much smaller size (if adult) and In the relatively larger size of its 

 phalanges, and consequently larger feet. Compare the transverse width of the distal end of the tibia and length of 

 a penultimate phalange in each. 



Tibia. Phalange. P. e. 

 Laelaps aquilunguis, 7 in. 4.75 ,67 



Laelaps maeropus, 4 in. 3.5 — .87 



The proximal phalanges differ also in their greater depth proximally, and in that their 

 inferior tubercle is expanded throughout the whole width of that extremity. The head 

 of the tibia hears on its exterior outline a tuberosity not seen in L. aquilunguis (a in the 

 outline, fig. 31). 



Fig. 31. 



A fragment of metatarsal is described by Leidy, 

 and the distal extremity figured. It appears to have 

 been the external one, and its condyle is directed 

 slightly outwards. It is flattened on the inner 

 face, indicating close contact with its fellow. The 

 proximal portion of another appears to be the ex- 

 ternal of the other side. It is also flattened on the 

 inner face, by an oblique plane which looks up- 

 wards and inwards, and which narrows distal ly. 

 Proximally it widens as the face of a, transverse 

 dilatation of the extremity, which gives the artic- 

 ular end a V shape. See fig. 32a (nat. si /,<>). To 

 this is added a infero-superior view of the same 

 extremity one-half nat. size, and fig. 33, an extero- 

 postcrior, and fig. 34 an extero-antcrior view of the distal extremity of the other. 



* Sec Hays' Medical Journal, I'hllaila., March, 1S68. 



