1909.] FROM THE BAY OF BISCAY. 851 



number of tlie sete and spines with which they were provided ; 

 but on comparing them with JSTorwegian specimens at the same 

 stage, taken in shallower water, a difference in size was at once 

 perceived, the Norwegian specimens measuring 12 mm. in length 

 as against the 10 mm. of the Irish ones. 



The classification followed is that of Stebbing's ' Das Tierreich : 

 Amphipoda.' 



The measurements of the whole animal in all cases are taken 

 from the tip of the rostrum to the tip of the telson. 



Fam. Pleustid.^. 

 Genus Parapleustes Buchholz, 1874. 



Syn. 1859. ParamphUJioe (^nvt) Bruzelius (7). 

 1860. „ Boeck (1). 



1865. „ Goes (16). 



1870. „ Boeck (2). 



1874. Parapleastes Buchholz (8). 



1876. Pkastes Boeck (3). 



1882. ParampUlkoe<<\. O. Sars (27). 

 1887. „ Hansen (17). 



1893. „ G. O. Sars (29). 



1906. NeopUustes Stebbing (40). 



In 1874 Buchholz founded the genus Parapleustes on the type 

 species P. gracilis. He recognised its near relation to the oldei- 

 genus Paramphitho'e Bruz., and stated (p. 337) that he had 

 hesitated as to the identity of his species P. gracilis with Boeck's 

 species Paramphitho'e glabra, but had decided that the differences 

 in the form of the body and more particularly of the mandibles 

 justified the institution of a new genus for it *. His account of 

 the genus, apart from the description of the mandibles which was 

 founded on eiror, agrees in every particular with Paramphitho'e. 

 The type species was later identified by Hansen (17) with 

 Paramphitho'e brevicornis Sars. That this identification is 

 correct, and that Buchholz's description and figures of the 

 mandibles are erroneous, I have been enabled to prove, thanks 

 to the courtesy of Dr. Vanhoffen and Dr. Hansen, by dissecting 

 one of Buchholz's type specimens of Paraqohustes gracilis and 

 comparing it with one of Sars's type specimens of Param- 

 phitho'e brevico7'uis. Sars, however, identified P. gracilis with 

 Boeck's species glaber, altering Buchholz's generic definition of 

 the mandibles from " vollig ohiie Spur eines Kauhcickers " to 



* " Ich muss gestehen, dass es mir etwas zweifelhaft bleibt, ob die uaclistebeiid 

 beschi-iebene kleine Ai-t von Ostgroiiland niit deii angefiihrteii Synonymen [? an : 

 Ampliithopsis glaher Boeck; ? Paramphithoe e.vigua does; Varamphithoe glabra 

 Boeck] ideutisch ist, da die selir kurzen Augabeii von Uoeck und Goi's hieriiber 

 betraclitliche zweifel bestehen lassen. Ich /.iehe daher vor, sie als neue Art y,u 

 beschriebeu und glaube sie mit der vorigen, wegeu der ziemlich betrachtlichen 

 Abweicliungen in der Bildung der Mandibeln und Korpert'ormen, nicht in derselben 

 Gattung vereinigeu zu konnen." Buchholz (8) p. 337. 



Puoc. ZooL. Soo.— 1909, No. LVIII. 58 



