226 Guide to Belfast. 



taken as a typical representative of the Isopoda, except that 

 its respiratory organs have been so mocHfied from the usual 

 form as to enable it to breathe on land, while most of the 

 members of the group are confined to the sea. Many 

 of the species are external parasites. Idotea balthica and 

 /. pelagica have both been taken in Belfast Lough ; while 

 two other species (viz., /. emarginaia and /. linearis) occur 

 on the open coast of the County Down. The much-dreaded 

 Gribble (Litnuoria lignorum), which burrows into wooden 

 piers, and is one of the most destructive Arthropods known, 

 has also been noticed in Belfast Lough. No less than 

 four species of Splucronui have been observed in the same 

 locality, and one of them ( S. serratiim) has migrated up the 

 River Lagan to a considerable distance. The freshwater 

 Asellus aqiiaticus is found not only in Lough Neagh but in 

 almost every ditch in the district. Gnathia maxillaris lias 

 been taken off Bangor, Co. Down, and Atlielges paguri in 

 Strangford Lough. Eurydice pulch7-a occurs in small rock- 

 pools at Carrickfergus; whereas Cirolana boj-ealis has been 

 taken off the halibut in Belfast Lough. Among other species 

 which have occurred in the Lough may be mentioned Auesa 

 Indenfata, Cytnodoce truncata, and C. emai-ginata . 



As for the terrestrial species of Isopods (the so-called 

 woodlice), we find a number of records for the two counties 

 in a paper recently published in the L-ish A^atia-alist} Ligia 

 oceanica abounds all round the coast ; while R. Welch has 

 taken Trichoniscus pusillus in Co. Antrim and the very 

 rare T. Toseus at Ballyfinder, Co. Down. Of the genus 

 Porcellio, only P. scaber is common ; but P. dilatatus has also 

 recently been discovered in a Belfast cellar by Mr. Buckle. 

 Onisais asellus and Philoscia muscoruni are common all over 

 the district. R. F. S. 



GEPHYREA. 



\n W. Thompson's time the Gephyrean worms, which 

 are all marine, were still looked upon as an order of the 

 Echinoderms, but they are much more closely related to the 

 Chtetopods, though thev include a somewhat heterogeneous 

 assembly of worm-like creatures. 



1 R. F. ScHARFF. — The Irish Woodlice. Irish Natumlisf, vol. iii, 1894. 



