436 Mr. E. T. Newton. [Dec. 7 y 



that the ends of the hydroccele meet round it, and the month is 

 approximated to the snbstratnm, so that the animal can feed on the 

 mud beneath it, which is impregnated with organic matter. 



It follows that the abactinal poles of Asterina and Comatula are not 

 comparable with each other, and that all conclusions based on the sup- 

 posed homology of the dorsocentral in Echinids and Asterids, and 

 that in Crinoids, are incorrect. 



II. " Reptiles from the Elgin Sandstone : Description of Two 

 New Genera." By E. T. NEWTON, F.R.S. Received 

 November 2, 1893. 



(Communicated by permission of the Director- General of the Geological Survey.) 



(Abstract.) 



Since the reading of the previous paper " On some New Reptiles- 

 from the Elgin Sandstone " (' Phil. Trans.,' B, 1893), the author has 

 received several additional specimens from the same formation in the 

 neighbourhood of Elgin, but not from the same locality, and repre- 

 senting other groups of Reptiles. Two of these specimens, being 

 new and interesting forms, are described in detail. One of them is 

 the property of Mr. James Grant, of Lossiemouth, and is contained 

 in a small irregular cube of sandstone. The bones themselves 

 having been dissolved out, as in the earlier described fossils, their 

 forms have been reproduced by gutta-percha casts taken from the 

 cavities left in the stone. This reptile was evidently a small Para- 

 suchian Crocodile, allied to Stagonolepis ; it is now represented by 

 the skull, which is about 3 inches long, and the anterior half of the 

 body, with the pectoral arch and both the fore limbs. The skull is 

 depressed, has a pair of supratemporal fossce and a pair of orbits 

 completely surrounded by bone, and in front of the latter, on each 

 side, a large prelachrymal fossa ; the two nasal openings are small,, 

 and placed near the end of the muzzle. The palate is narrow and 

 deeply grooved, with primitive posterior nares placed far forwards. 

 The teeth vary in size, are slender, conical, and recurved, and re- 

 stricted to quite the anterior part of the upper jaw. The vertebrae 

 are slightly biconcave ; the 9th has distinct double articulations for 

 the ribs, but how far this character extended forward is uncertain. 

 The scapulas are long and slender, while the coracoids are short and 

 wide. There is an interclavicle. The humeri have each a strong 

 pectoral crest, and are Crocodilian in form ; the radius and ulna are 

 slender bones ; the carpals are indistinct ; five metacarpals are 

 present on each side, bat only a few of the phalanges are to be seen. 

 Above the vertebrae there is a double row of small, pitted, and closely- 

 set scutes. This small Parasuchian is named Erpetosuchus Granti. 



