374 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOAV. 



occurrence being as follows : " We believe that this 

 species has only hitherto been found in Mr. C. 

 Spence Bate's courtyard and cellar, and that of 

 neighbouring houses at Plymouth, where it is 

 tolerably abundant"* 



Idotea pelagica. Leach. — I have frequently seen 

 this species at Tarbert; but, until a few days ago, 

 I had not examined it, thinking it to be the young 

 of /. tricuspidata, which is common enough. Having 

 detected some females with ova, how^ever, I was led 

 to examine the animal more closely, Avith the result 

 that it proved to be /. pelagica. The lower antennae 

 are shorter and stouter than those of /. tricuspidata^ 

 the flagellum is hairy, and it w^ants the tricusped 

 form of the tail of that species. 



It is said to be " common on the Bell Rock — 

 probably common all round the coast in the 

 laminarian zone." f I have frequently found it 

 above low-w^ater mark about empty barnacle-shells. 



Anceus sp. — Canon Norman says he does not recog- 

 nise this as among the described species of the 

 genus. The only specimen which has yet been 

 obtained was dredged by me in East Loch Tarbert 

 early in December last. The following is a descrip- 

 tion of it. 



Length about '14 of an inch. Cej)halon nearly 

 twice as broad as long, considerably depressed in 

 front, the depression extending backwards and 

 upwards so as to form a concave sloj^e ; eyes 

 lateral and close to anterior edge of cexihalon. 

 Mandibles large, blunt pointed, length from anterior 

 edge of cej^halon about ^ of the wdiole, broad near 

 proximal end; inner edge of each nearly straight, 

 abruptly narrowed near base by a rectangular 

 constriction to about half the width of the portion 

 immediately above ; outer edge concave, curving 



* Bate and Westwood, I.e., ii. 241. 

 \ Id., ii. :^5. 



