PERACARIDA iMYSlDACEA-) AND EUCARIDA iDECAPODA-) 79 



NOTES ON SOME OF THE PERACARIDA {MYSI- 

 DACEA) AND EUCARIDA {DECAPODA) OF 

 ST ANDREWS, IN THE LIVING CONDITION. 



By Prof. M'iNTOSH, F.R.S., &c., Gatty Marine Laboratory, St Andrews. 



The following notes on the living Crustacea were made for 

 the most part in the early sixties of last century when work- 

 ing up the marine fauna of St Andrews, and they have been 

 verified on various occasions since that date. The region is 

 characterised by the presence of many edible Crabs and of 

 the Lobster, by the frequency of Lithodes nuria, Corystes 

 cassivelauniis, and Hyas coarctatus in the deeper water of the 

 Bay. Micnida is rare, only a single specimen having been 

 procured in deep water, and that since the publication of the 

 Marine Invertebrates and Fishes. GalatJiea squaniifera is 

 common between tide-marks chiefly at the Castle rocks 

 As pointed out in the work just quoted, St Andrews forms a 

 bold contrast in its Peracarida and Eucarida on the one 

 hand with the Zetlandic area, and on the other with the 

 Channel Islands, whilst it likewise differs from the Outer 

 Hebrides and the western shores. Each of these areas is 

 characterised by certain peculiar types which are absent 

 from St Andrews. 



Mysidacea. 



Mysis Jiexieosa, O. F. Miiller. It is curious that Bell does not 

 mention this species from Scotland, yet it is by far the commonest 

 form. Some show a pretty pink tint on the two terminal segments 

 of the tail. 



Afvsis vulgaris, J. V. Thompson. The tail is rather ovato- 

 lanceolate than lanceolate, as Bell states. The peduncle of the 

 antennules has its widest part at the bifurcation, and the scale of the 

 antenna is only about two and a half times as long as the peduncle, 

 thus differing from Bell's description. 



Mysis grijjitiisice, Bell. ^These long, slender, pale forms have a 

 brownish dot behind the eye and a few similar specks along each 

 side of the abdominal segments, the pigment being symmetrically 



