222 ANNALS OF SCOTTISH NATURAL HISTORY 



GNATHIA MAXILLARIS (Montagii). 



This Isopod, which is moderately common, is more familiar 

 under the name of Anceus maxillaris. Gnaihia is the generic 

 name established by Leach in 1814, and must, as stated by Professor 

 Sars, be preferred to that of Anceus or Praniza. Anceus (Praniza) 

 Edwardii, Spence Bate, is, according to Sars, only the female of 

 Gnathia maxillaris. 



ClROLANA BOREALIS, Lilljeborg. 



This is the form described in Bate and Westwood's " Sessile-eyed 

 Crustacea " as Cirolana spinipes. Dr. Robertson records it from the 

 Clyde, and Mr. Gregor has taken it in the Moray Firth. I have 

 also observed it in both these districts. (Cirolana Chranchii, 

 Leach, has also been recorded from the Clyde by Dr. Robertson, 

 but this species I have not yet observed.) 



IDOTHEA BALTICA, Pallas. 



This Isopod is more generally known under the name of 

 Idothea tricuspidata, Desmarest. Professor Sars adopts Pallas's name 

 as being prior to that of Desmarest, and also in preference to Idothea 

 (Outsells] marina, Linne, because he considers it very doubtful if 

 the Linnean name refers to this species. Idothea baltica, it is hardly 

 necessary to add, is the most common of our " Sea-sclaters." 



IDOTHEA PELAGICA, Leach. 



The present form has been included with /. baltica under the 

 common name of /. marina as not being specifically distinct ; but 

 Professor Sars remarks that it could not have been the true Leachian 

 species that had been under examination, as it is impossible to con- 

 found that species with /. baltica. Idothea pelagica appears to be 

 much less common than the other ; it is also considerably smaller in 

 the adult stage. Dr. Robertson records this species from Cumbrae, 

 Firth of Clyde, and states that it has been taken at various localities 

 on the English, Scottish, and Irish coasts. In 1886 I collected a 

 number of specimens, male and female, at East Loch Larbert, Loch 

 Fyne. Some of the latter which carried ova did not exceed 7 milli- 

 meters in length. 



I would note in passing that there are two other species of 

 Idothea described by Professor Sars that may also occur on the coast 

 of Scotland, viz. Idothea neglecta, G. O. Sars, and Idothea viridis 

 (Slabber). The first is not unlike /. pelagica in general appearance, 

 but is larger, and has the inferior antennae longer and more slender ; 

 this species is more or less abundant along the whole Norwegian 



