I. '08. 154 



evidently distinct from any Irish examples of P. hispinosus that, 

 notwithstanding Appellof's statements (1906, ]). 180), I was 

 convinced that two well-defined species were represented ; but 

 recently, after a close examination of a very large number of 

 specimens from Canon Norman's museum, 1 have been forced 

 to alter my views on the subject. From the examples collected 

 by Canon Norman it is easy to select a series showing every 

 possible intermediate form between P. hispinosus and 7ieg- 

 lectus. 



Typical specimens of the var. neglectus are characterized by 

 the perfectly smooth carapace w^ithout trace of tuberculation 

 on the dorso-lateral ridges or elsewhere ; under a high power 

 the general surface is seen to be very finely reticulate wath 

 numerous minute depressions and punctures. The posterior 

 spine in the median line of the carapace is reduced to an 

 obscure tubercle or is wholly obsolete. The rostrum is slightly 

 more rounded at the apex than in P. hispinosus and the grooves 

 on the carapace are rather less distinct. 



The colour in life of the Irish specimens, which are in every 

 feature typical of the var. neglectus, is as follows : — The cara- 

 pace is uniformly pale, pale w^ith a sprinkling of brown dots, 

 or uniform dark chestnut brown. The abdomen is pale, with 

 a transverse chestnut brow^n band across the fourth somite ; 

 the pleura and pleopods show dark mottling. On the telson 

 and uropods there is a narrow^ transverse brown band consist- 

 ing only of a pair of chromatophores on the telson and one on 

 each of the uropods. 



The brown banding cannot be considered at all satisfactory 

 as a specific character. It is wholly absent in two recent well- 

 marked examples of the var. neglectus which were caught in 

 the Bay of Biscay and, as already stated, similar colouring 

 frequently prevails in P. fasciatus and P. sculptus and has 

 once been observed (v. p. 153) in a typical hispinosus . 



Practically all the specimens which Canon Norman has so 

 kindly permitted me to examine showed a certain amount of 

 surface spinulation ; in the case of the better marked examples 

 of the var. neglectus this was, of course, exceedingly obscure, 

 but certainly no individual was found to possess as smooth a 

 carapace as the Irish specimens. 



In course of time it will perhaps be found that the relation- 

 ship between P. hispinosus and neglectus is somewhat of the 

 same nature as that which seems to exist between Spiron- 

 tocaris spinus and S. Lilljehorgi, and that the two forms are 

 quite distinct in certain areas, w^hile in others they occur in 

 company with intermediate forms. 



Size. — Three of the Irish specimens are ovigerous females, 

 and are 13 J, 14 and 15 mm. in length; the fourth specimen 

 is a male, and measures 14 mm. Scott (1902) records a speci- 

 men of 18 mm. 



General distrihution. — This rare form was first described 

 by Sars from the west coast of Norway. It has been four 

 times recorded from the coasts of Scotland : by Norman (1887) 



