THE LINGUATITLID ARACHNID RAILLIETIBLLA FURCOCERCA. 15 



3. On the Linguatulid Arachnid Raillietiella farcocerca 

 [Diesing, 1835] Sanibon, 1922. By George S. 

 GiGLiOLi, M.D. Pisa. 



[Received November 1, 1922 : Read February 6, 1923.] 



This species was described by Diesing in 1835 under the name 

 of Pentastoma furcoG87-cum, from specimens collected by batterer 

 in South America, His original description, translated from the 

 German, runs as follows : — 



"The worms are from 9 to 10 lines in length; 1 line thick 

 at the anterior extremity, i at the posterior. They are grey in 

 colour, while their internal organs, which can be seen in trans- 

 pai-ency, are brown and somewhat marked in white and reddish. 

 The body is spindle-shaped and presents a linear annulation, 

 which is most marked at the middle part of the body, while it 

 gradually disappears towards the two extremities. On each ring 

 are numerous stigmata disposed along a line at regular intervals. 

 The cephalic extremity is somewhat flattened and is obtusely 

 triangular. At its apex it presents the oval oral opening. The 

 hook-pouches, which are situated symmetrically behind the mouth, 

 are borne by obtusely conical structures. Each pouch is pro- 

 tected by three rounded pads, two lateral and one median, which 

 is situated over the hook. Each pouch contains two hooks, pro- 

 bably united at their base ; they are situated one over the other. 

 The upper one is nearly straight and short ; the lower one is 

 longer and more medially directed. The posterior extremity is 

 bifid. The male can be distinguished from the female by the 

 penis, situated on a papilla on the mid-ventral line on the first 

 anterior ring. I have found the two caudal points divergent in 

 a female, but the two sexes are similar in size." 



Later, in his ' Systema Helminthum,' Diesing again describes 

 the same species under the name Pentastoma hifurcatum : — 



" Corpus subfusiforme retrorsum attenuatum, extremitate 

 caudali bifurcatum, annulato-plicatum, annulislinearibus. Caput 

 obtuse triangulare depressiusculum. Os ovale margine lato cal- 

 loso apice truncato, inter bothria obtuse triloba in formam coni 

 trunca,ti disposita situm. Hamidis insequalibus. Long. fern. 

 9-13'"; crass, antice ultra 1'"; postice j'". Femina cauda sua 

 bifurcata, in aliis emarginata, marem multo minorem et gracili- 

 orem sub coitu probabiliter excipit." 



In 1898 Sir Arthur Shipley, in his monograph on Lingua- 

 tulidse, reproduced Diesing's description under the name Poro- 

 cephalus h^fm'catum. 



In 1910 Sambon included this species in the genus Raillietiella, 

 and, following the rule in zoological nomenclature, again adopted 



