On the Nomenclature of Echinoids. 117 



22. x. 1890 (Lt.-Col. Yerbury) ; and one <$ from Colombo, 

 Ceylon, October 1898 (E. E. Green). 



The types of both sexes are in the British Museum 

 (Natural History). 



Writing on November 1st, 1909, with reference to Musca 

 pattoni, Captain Patton said : — " This species breeds in cow- 

 dung, and its pupa is dirty white. The fly has peculiar 

 habits, in that it sucks the blood which oozes from the bites 

 inflicted on cattle by Hcematopota and other Tabanids, 

 Stomo.vys, and Philtematomyia. It likewise sucks the juice 

 out of the vaccine vesicles on calves, and also the blood 

 after the vesicles are scraped." 



From Musca domestica, L. (syn. M. determinata, Walk.), 

 M. pattoni can be distinguished, inter alia, by its usu illy larger 

 size, stouter habit of body, much narrower front in the male, 

 the greater breadth of the sides of the front in the female, 

 and the more sharply defined median stripe on the abdomen 

 in both sexes. The fact that the first segment of the 

 abdomen is in both sexes for the most part ochraceous-buff 

 or buff, instead of entirely or for the most part black or 

 bronze-black, will serve to distinguish Musca pattoni from 

 M. corvina, Fabr., and other species closely allied thereto. 

 From Musca nebulo, Fabr., — which, according to Captain 

 Patton, is "the common Musca of Madras, breeds in horse- 

 dung and other refuse, particularly in night-soil, and has a 

 reddish- brown pupa," — M. pattoni differs, inter alia, in its 

 much larger size, in the front of the male being only half or 

 less than half as wide, and in the presence of the clove- 

 brown mark on the apex of the fourth abdominal segment. 

 In M. nebulo the fourth segment of the abdomen, or at least 

 its apex, is entirely pale. 



XVI. — On some Points in the Nomenclature of Echinoids. 

 By Dr. Th. Mortensen. 



The nomenclature of Echinoids has received considerable 

 attention of late years, and a great number of publications 

 dealing more oi less extensively with problems relating 

 thereto have appeared. Unfortunately the result of these 

 discussions has been by no means a general agieament on 

 these questions among specialists. It is true that recently 

 most of the authors seem to have come to an agreement on 

 some important points; but now Lambert and Thierj, in 

 their ' Essai de nomenclature raisonnee des Echinides ' and 



