HAUGHTON ON THE SEA-LOUSE OF THE BALTIC. 61 



A paper was then read, of which the following is an abstract : — 



The Sea-Louse of the Baltic By the Rev. Samuel Haughton, M. D., 

 Fellow of Trinity College, Dublin. 



He exhibited to the meeting some fine specimens of that animal 

 (Oniscus entomon, Linn.), dredged by Mr. Graves, of Liverpool, and him- 

 self, off Stockholm and Helsingfors. He stated that they were only 

 found on a bottom composed of decayed timber, generally fir, and that 

 Professor Greene, of Queen's College, Cork, had identified them with 

 species described by Linnaeus and Pallas. It was curious that, with 

 the exception of this Crustacean, and a few dwarfed Tellinse, the Baltic 

 should be so barren a field for the naturalist's dredge ; and there could be 

 little doubt that the scarcity of fish in many parts of that sea was to 

 be explained by the corresponding scarcity of Mollusks and Crustaceans. 

 Linnaeus had noticed that the Sea-Louse frequented particularly those 

 parts of the Baltic which were visited by the shoals of herrings. 



" Oniscus entomon, abdomine subtus nudo, cauda subulata. 



Oniscus cauda subulata utrinque appendiculata. — Pn. 1255. Raj. 

 ins. 43. 



Assellus marinus cornubiensis alius. Act. Ups. 1736, p. 39, n. 1. 



Oniscus marinus maximus. Klein. Dub. 38, f. 1, 2. 



Entomon pyramidale. Suecis Syrmask — Ostrobotniensibus Grunds- 

 korfwa. Habitat in mari Baltico cum harengis frequens. 



Descriptio : — Magnitudinis extremi articuli pollicis, supra convexus, 

 infra planus, margine undique acuto. Capitis clypeus undique incisus 

 est. Pedes anteriores utrinque tres, minores, glabri ; posteriores utrin- 

 que quatuor, majores, ciliati. Antennarum in fronte bina paria. Cor- 

 pus septem incisuris, prseter caput et caudam. Cauda duas tertias 

 partes corporis longitudine aequat, indivisa, tereti-triangularis, subtus 

 vestita radiis duobus convexis, parallelis. Totum animal, exceptis 

 oculis, album." — Zinnceus, Fauna Suecica: Stockholm, 1761, p. 499. 



The President remarked that it would be always of importance if 

 yachting men were to take an interest in noting the soundings of re- 

 markable localities they might visit, and be provided with dredges and 

 small trawl-nets. They have opportunities, from facilities of range and 

 of leisure, that would enable them to trace more interesting experiments 



