FLABELLIGEBA AFFINIS 118 



he found two oral apertures, and two gullets — since he considered the cardiac body as 

 one of them. His figures are artistic though perhaps not quite accurate. His views were 

 adversely criticised by Maximilian Midler 1 (1852), who pointed out that Otto had mis- 

 taken the anterior vascular trunk for a second oesophagus. He described and figured 

 the caecal appendage of the stomach as somewhat spiral. The segmental organs were his 

 salivary glands. 



When a theological candidate in 1829 the elder Sars 2 introduced this species to 

 science in a careful description accompanied by recognisable figures. 



Dujardin (1839) found this form on the shores of the Channel, and described and 

 figured it under the name of Ohlormma Edwardsi. His figures of the hooks, bristles, 

 and papillas are fair. 



Leuckart (1849) gave details of its structure. He could not find the opening of the 

 so-called accessory organ (heart-body), which Rathke thought to be a salivary gland. He 

 considered it might be homologous with the Polian vesicles of Echinoderms. 



Kolliker, in 1864, mentions that he procured Svphonostomum diplochaitos at Millport, 

 but in all probability this was the common species. He gives an account of the papillse 

 with a figure. 



The Ghlormma pellucidum of Sars (1873) does not seem to differ materially from 

 the present species. 



A memoir on the structure of Si/phonostoma diplochdetos, Otto, by Jourdan 3 

 appeared in 1887. He gives an interesting description of the general anatomy, and 

 especially of the minute structure of the four eyes over the brain, and the circulatory 

 importance of the investment of the gastroesophageal cascum, for so he called the 

 heart-body, which he diagnosed as an appendage connected with the oesophageal canal, 

 whilst its "couche peripherique " was muscular, contained blood, and pulsated rhythmi- 

 cally like a heart. 



Cunningham and Ramage (1888) mention six pairs of gonads, the longer posterior 

 ones being bound together with the loop of intestine into a cylindrical mass. The 

 ovaries are green, and the testes white. 



Dr. H. C. Sorby 4, (1906) found this species swimming in considerable numbers near 

 the surface in the Orwell, and as those kept alive voided ova, he thought that they had 

 assumed the pelagic state to disperse their ova. 



This differs from F. diplochaitos, Delle Chiaje, from Naples, in the shape of the 

 papillae, which have much more elongated " heads " or ends than in the British form, and 

 these, with the urn-shaped extremities, are also proportionally longer. Instead of a 

 single hook as a rule occurring ventrally the Neapolitan form has two or three, and 

 the hooks themselves offer certain differential features, such as the greater length 

 and slenderness in the southern form (Plate CIV, fig. 2), their pallor, and the more 

 uniform outline of the hook at the tip. All these features, however, may be the 

 result of modification in different surroundings, just as it is found that the transverse 

 segmentation of the hooks vary much in the British forms. 



1 ' Observ. Yerm. quib. Marin./ p. 7, Tab. ii, figs. 1-18. 



2 'Bidrag. til soedyrenes Naturhist./ Bergen, 1829, p. 31, Tab. iii, figs. 16-19. 



3 ' Annales Musee Hist. Nat. de Marseille/ vol. iii, pp. 1 — 43, 4 pis. 



4 ' Journ. Linn. Soc./ vol. xxix, p. 437. 



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