Zoology. 1 87 



The rarest species in the local fauna is the Nudil)ranch 

 Lamellidoris ulidia/ia, found by Mr. Thompson on oysters 

 from Down or Antrim, and not known elsewhere. Two — 

 Homalogyra atomus var. polyzona, and Lamellodoris muricata 

 — are, so far as at present known in the British Isles, con- 

 fined to our district — the first to Antrim, the second to both 

 counties. Three more Antrim species — Turbonilla pusilla 

 var. de/ica/a, Lepton obliquatum^ and Niiciilana pusilla — 

 though found elsewhere in Ireland, are unknown in Great 

 Britain. The list of Down and Antrim Mollusca unknown 

 elsewhere on the Irish coast numbers eight species : 



N Craspedochilus (Chiton) albus. 



N *Scissurella crispata. 



s Homalogyra atomus var. polyzona. 



s Jordanula (Odostomia) truncatula. 

 Galvina (Eolis) tricolor. 



N Lamellidoris (Doris) muricata. 

 Lamellidoris ulidiana. 

 *Lima elliptica. 

 Of these, the species which are of distinctly northern or 

 southern range are distinguished by the letters N or S 

 respectively ; the two marked thus (*) have also been 

 dredged in deep water off the west coast. 



In giving a brief indication of the distribution of the rarer 

 species, a division according to the two counties which 

 compose the district is not satisfactory, so many species 

 having been taken in Belfast Lough, which lies between Down 

 and Antrim. A tripartite division into North, Mid, and 

 South has therefore been adopted. Mid (M), signifies the 

 Belfast Lough area, stretching, say, from the Maiden Rocks 

 to the Copeland Islands ; N, the waters north of this ; 

 S, the waters south of it. Where the names in the follow- 

 ing list of rarer species differ from the familiar ones of 

 Jeffreys' British Concliology, the latter, whether generic or 

 specific, are added in parenthesis. 



List of Rarer Species. 

 N M Spirula Peronii Lamk. 



M Rossia macrosoma {delle Chiaj'e). 

 M s Todaropsis (Loligo) EblanK [Ball). 



