464: Dr. T. Scott on British CopepoJa. 



with those previously noticed in the female, render tlio 

 removal of tliis species from the genus Ci/liudropsi/llus 

 necessary, and the new geims I propose for its reception is 

 named D' Arci/thompsonia in compliment to Professor D'Arcy 

 Wentworth Thompson, C.B., of University College, Dundee. 



Genus Harrietella *, T. Scott, nov. 

 (PL X[. tigs. 9, 10.) 



An apparently new species of Gopepod is described in 

 part iii. of the ' Twelfth Annual Report of the Fishery Board 

 for Scotland.' This Copepod was provisionally ascribed to 

 the genus Laophonte, Philippi, with which it partly agrees. 

 It was mentioned, however, in some general remarks on the 

 species that there were certain im|)ortant ditfefences that 

 could hardly be reconciled with the definition of that genus ; 

 but as only one or two specimens had been obtained, I pre- 

 ferred to leave it in that genus till additional examples should 

 be procured. The first specimens were obtained within the 

 valves of a dead Lamellibranch [Cyprina) shell dredged in 

 the Firth of Forth, but others were afterwards found in 

 considerable numbers in the Firth of Clyde in the crevices of 

 partly decayed wood brought up in the trawl-net, and it is in 

 ))ieces of submerged and partly decayed wood I now most 

 frequently find the species. An examination of these 

 additional specimens showed that the differences referred to 

 were not accidental, but characteristic of the species, and that 

 the species could not be retained in the genus Laophonte. I 

 now therefore propose to remove it from that genus to the 

 one described below. 



Description of the genus Ilarrietella. — Female. Body tole- 

 rably robust, cephalothorax dejjressed, greatest vvidtli fully 

 half the entire length of the animal ; abdomen narrow. An- 

 terior antetuias short, six-jointed. Posterior antennae short, 

 two-jointed ; outer ramus small and uniarticulate. Mandibles 

 small and narrow, apex truncated and provided witli a few 

 small teeth. The other mouth-organs similar to those in 

 Laophonte. The first three pairs of thoracic legs, which are 

 tolerably robust, have the inner branches two- and the outer 

 tliree-jointed. In the first pair the inner branch is elongated, 

 the first joint being considerably longer than the entire outer 

 branch ; the second is short and armed with a stout terminal 

 claw, as in Laophonte. In the second and third pairs the 



* This genus is named in compliment to Miss Harriet Richardson, 

 author of 'A Monograph on the Isopods of North America.' 



