18 TERETULARIA. 



naria longiceps of Duges {Ann. des Sc. Nat. xxi. 83 (1830), pi. 2. 

 f. 21 ; Dies. Syst. Helm. i. 207). 



"Prostoma? armatum?, translucent and gelatinous, with the 

 cephalic points orange, and scattered irregularly. 



Prostoma armatum, Templeton in Loud. Mag. Nat. Hist. ix. 236, 

 f. 29 a. Johnston in Ann. 8f Mag. Nat. Hist. xvi. 436. 



Hab. "Found among Conferva spiralis from a drain in the bog 

 meadows," near Belfast. — Templeton. 



Obs. The anterior end is rounded and almost orbicular ; the pos- 

 terior oblong and obtuse. The eyes extend a good way down the 

 body, which appears to be about 2 inches long ; but it is probably 

 represented considerably magnified. The species has no resemblance 

 to the Prostoma armatum of Duges ; but it seems to be a member 

 of the genus as now restricted. 



Cercaria. 



Cercaria, Dalyell, Pow. Creat. ii. 266. pi. 36. f. 9. 

 Hab. Fresh water. 



Desc. "This is a minute animalculum, somewhat resembling a 

 Planaria, with an annulated tapering tail. The mouth is an orifice 

 in the centre of the anterior extremity. The body is of mutable 

 form, the tail very extensile, when the rings are almost obliterated. 

 Colonies of these animals, like white specks, dwell in fresh water." — 

 Dalyell. 



II. TERETULARIA. 



Teretularia, Blainville in Diet, des Sc. nat. Ivii. 573 (1828). 



NEMERTiE, Ann. <5* Mag. Nat. Hist. xiv. 33 (1844). 



Cestoidina, Oersted, Entw. Plattw. 7^ (1844). Ray Soc. Rep. 



Zoo^. 1847, 514. 

 Nemertina, Oersted, Entw. Plattw. 80. 

 LiNiNiE, Johnston in Ann. ^ Mag. Nat. Hist. xvi. 434 (1846). 

 Nemertea, De Quatrefages, Voy. en Sidle, ii. 95. 

 Nemertines, E. Blanchard in Ann., des Sc. nat. viii. 123 (1847). 

 NEMERTiNiDiE, T. WHUams in Rep. Brit, Assoc. 1851, 238; and 



in Ann. Sf Mag. Nat. Hist. ser. 2. xii. 342 (1853). 

 Nemertinea, Diesing, Syst. Helm. i. 238. 

 Rhynchoccela, S. Schultze, Beitr. Turbell. 3. 



Obs. In the present state of our knowledge of this suborder it 

 cannot be advantageously divided into families. The structure of 

 many species has been demonstrated, but anatomists differ widely as 

 to the function of the organs described ; and hence I have avoided 

 their nomenclature, lest error should be thus continued. It may 

 be considered as proved that the mouth is terminal ; and, in many 



