I '08. 161 



pereiopods, arid plcopods are thickly spotted with red, the 

 antennal scale and antennules being more sparsely dotted with 

 the same colour. 



Size.— The largest specimen examined is 52 mm. in length. 

 Off the Irish coast this species appears to grow to a large size 

 only in comparatively shallow water (60 fathoms or less). 



Very small specimens, of from 10 to 15 mm., from deep 

 water off the west coast, invariably possess the two small ad- 

 ditional teeth in front of the median anterior tooth ; the ros- 

 trum is deeply hollowed above and in side vie"\v arched, with 

 its lateral spines much more pronounced than in large speci- 

 mens ; the antennal scale also is narrower, externally slightly 

 concave, its apical spine not reaching beyond the lamellar por- 

 tion. 



A curious variation in the armature of the carapace occurs 

 in the case of an example 10*5 mm. in length from 74 fathoms, 

 30 miles W.N.W. of Cleggan Tower, Co. Galway. Here the 

 posterior tooth of the median line and the middle tooth of the 

 first lateral are entirely missing. In all other respects, how- 

 ever, this specimen bears the closest resemblance to the small 

 forms mentioned above, so that I have no hesitation in regard- 

 ing it merely as an abnormal example of P. spinosus. 



General distribution. — Pontophilus spinosus is known from 

 south and west Norway as far north as lat. 62° 35' (Sars, Nor- 

 man, etc.), S. of Iceland (Hansen), Sweden (Goes), Denmark 

 (Meinert) and generally throughout the North Sea. It has 

 been recorded from the Bay of Biscay (CauUery) and has been 

 repeatedly found in the Mediterranean and Adriatic (Senna, 

 Heller, etc.). 



Off the English and Scotch coasts this species is moderately 

 common , extending from the extreme south as far north as the 

 Shetland Is. 



Irish distrihution. — Not uncommon on the east coast trawl- 

 ing grounds outside the 20-fathom line, and equally plentiful 

 off' the south and west coasts. 



Vertical range. — Found off' the east coast in 10 to 73 

 fathoms ; in the west the species has been trawled in as much 

 as 244 fathoms. In the Mediterranean P. spinosus occurs in 

 much deeper water, x\densamer records it from 664 fathoms 

 and Senna from 863 fathoms. 



