542 Dr. H. Woodward — M. Cambrian Fossils of the Rockies. 



Anomalocaris (gen. nov.). — "Carapace audits appendages unknown 

 or too obscurely indicated for their characters to be defined ; body- 

 many jointed and consisting of not less than nine to thirteen 

 segments, exclusive of the caudal segment ; ventral portion of 

 each of the body-segments bearing a pair of slender, narrowly 

 elongated and acutely pointed, simple and probably branchial 

 appendages, of the nature of uropods, or foot-gills (?) ; posterior terminal 

 segment margined with three pairs of caudal spines, one terminal 

 and the other two lateral ; the posterior pair of uropods represented 

 in the woodcut apparently belonging to a pre-caudal segment whose 

 posterior boundary has been obliterated. 



Fig. 7. — Anomalocaris Canadensis, Whiteaves (1892). Three -fourths nat. size 

 (anterior part of carapace conjectural). Drawn by Miss G. M. "Woodward 

 from a specimen in very dark shale from the Middle Cambrian of Mount 

 Stephen, obtained by Edward Whymper, Esq., F.R.G.S., in 1901. 



" Body, inclusive of the tail, elongated, slender, decreasing slowly 

 in size from the anterior to the posterior end, rather strongly curved 

 posteriorly and nearly straight anteriorly, the length of the portion 

 preserved varying in different specimens from nine to ten centimetres 

 (as measured at from about the mid-height and following the curve 

 of each), and the height or depth at- the imperfect anterior end from 

 twelve to seventeen millimetres, exclusive of the ventral appendages. 

 Body or abdominal segments, which in all the specimens collected 

 are abnormally flattened laterally, a little higher or deeper than 

 long, broader above than below; the pair of ventral appendages are 

 straight and prolonged downward at almost a right angle to the 

 main axis of the body, for although there is a slight divergence in 

 each pair, neither are directed distinctly backward nor forward. 

 Between each pair of segments there is evidence of a wedge-shaped 

 or very narrowly triangular lateral area or interval,^ which is 

 broadest or widest below and does not seem to extend quite to the 

 dorsal margin. At the posterior end the segmentation is very 

 obscurely defined. Caudal spines, which are simple, slender, 

 longitudinally elongated, and acutely pointed, averaging 6 mm. 

 in length by about 1 mm. in breadth at the base ; the three pairs 

 of spines about, equal in length, though the two lateral ones are 

 placed farther forward than the central and terminal pair. Surface 

 markings entirely iinknown. 



"This genus and species are based upon upwards of fifty specimens 



^ This space appears to have been occupied by a membranous connection which 

 united the harder tergal portion of each somite to its fellow ; the integument, however, 

 must have been very thin, probably like that of Aptis and Branchipus. 



