[MATTHKw] STUDIES ON CAMBRIAN FAUNAS 185 



Angelin's species. He was so good as to obtain from his artist, Mr. G-, 

 Liljevall, a beautifully drawn figure of the type of the genus ; this is 

 reproduced as an etching on one of the accompanying plates (PI. ITT., 

 figs. 7 a and 6). The description of the species found at Hastings Cove 

 is as follows : 



DoLicHOMETOPus AcADicus, n, sp. (PI. TIT., tigs. Qa to rf.) 



Body covered with a very smooth test. 



Head-shield margined all round and having an intra-marginal 

 furrow. T^yes large, furnished with a semi-circular orbital lobe. The 

 facial suture curves backward and downward behind the eyes, and has a 

 direct extension forward before the eyes. Glabella distinctly outlined, 

 bent downward in front, sub-clavate, without furrows, rather squarish in 

 front, extending to the anterior marginal fold, about twice as long as the 

 width at the base. Occipital ring lenticular in outline, divided from the 

 glabella by a shallow furrow. Fixed cheeks narrow, width about half of 

 that of the glabella at the base. Posterior angles of the middle piece 

 produced backward and bent downward. The eyelobes are as long as the 

 width of the glabella in front. 



Tn the confused mass of parts of trilobites, with which the lentiles at 

 Hastings Cove are filled, there seems to be a somewhat definite association 

 of a Paradoxides-like cheek with the head of Dolichometopus ; the flat- 

 tened margin is nearly as wide as the area within ; the cheek has no 

 posterior border fold, and it terminates in a flat ear-like spine ; it thus 

 resembles the movable cheek of an Anomocare ; the long eyelobe which 

 marks this cheek seems to indicate that it belongs with the head-piece of 

 Dolichometopus. 



A pygidium, which also occurs with the above heads and cheeks, is 

 not unlike that of an Anomocare, but differs in having a blunter and 

 stouter rachis than it is usual with pygidia of this genus ; we regard it 

 as probably the pygidium of the Dolichometopus. It has a rather narrow, 

 prominent rachis, having four faintly marked rings, beside the more- 

 distinct half-ring in front ; the side lobes have three faintly marked ribs, 

 beside that at the front margin ; the lateral margins are flattened and 

 without a fold. 



Sculpture. — This consists of a minute granulation, made visible oiily 

 with a lens. 



Size. — Length of the head-shield, 11 mm. ; width of the middle piece 

 of the head, 10 mm. Length of the movable cheek, 10 mm. ; width,. 

 5 mm. Length of pygidium, 6 ram.; width, 10mm. 



Horizon. — The conglomerate limestone bands in the gray shales.. 

 Frequent. 



