125 



rounded by a circular instead of a trigonal lip ; the Strong. trigono- 

 cephalus is placed by lludolphi in the section c, ore nudo, while 

 the armature of the mouth, in the present species, is so remarkable, 

 as to induce me to regard it as the tj'pe of a new genus, which I pro- 

 pose to denominate Gnathostoma* . 



" Gen. Char. Corpus teres, elasticum, utrinque attenuatum. Caput 

 unilabiatum, labio circulari tumido integro ; os emissile, processibus 

 corneis maxilliformibus duobus lateralibus denticulatis. Genitale 

 masculum spiculum simplex, ad basin papillis cireumdatum. 



" Sp. Gnath. spinigerum. Gnath., capite truncato, corporeseriebus 

 plurimis spinulorum armato. 



" The generic difference indicated by the external peculiarities of 

 the Entozoa above described, is confirmed by the internal anatomy, 

 ■vvhich presents some peculiarities which appear not to have been 

 hitherto detected in the class Entozoa : I refer more particularly to 

 a distinct salivary apparatus, conformable to that •vvhich exists in the 

 Holothuria and other E chinodermata. This apparatus consists of four 

 elongated straight blind tubes, each about two lines in length, \vhich 

 are placed at equal distances around the comraencement of the ali- 

 mentary canal, having their smaller extremities directed forward, 

 and opening into the nfiouth, at the base of the lateral tridentate 

 processes, and their closed obtuse ends passing backwards into the ab- 

 dominal cavity. When examined -vvith a lens of -^ inch focus, the 

 parietės of these salivary tubes present very distinct obliąue or spirai 

 decussating fibres ; their contents are semi-pellucid in the recent 

 ■vvorm, but become opake in spirit of wine. 



" The coexistence of these salivary glands \vith an orai apparatus 

 which is better adapted for trituration than any that has hitherto 

 been detected in the Entozoa, is conformable to the laws -vvhich re- 

 gulate the existence and condition of the salivary apparatus in higher 

 animals ; and is highly interesting on that account. The only allu- 

 sion which I can find to salivary organs in other Entozoa is in Clo- 

 ąuet's 'Anatomie de VAscaride Lombricoide ,' in vvhich he considers the 

 thickened glandular parietės of the asophagus to serve for an analo- 

 gous secretion. 



" The first portion of the alimentary canal or stomach, is about 3 

 lines in length ; it contains a milk-white substance, and is separated 

 by a •vvell-marked constriction from the reraaining portion, which we 

 may regard as intestine : this is fiUed Avltb a pulpy substance of an 

 amber colour, ■vvhich grows deeper in tint as it approaches the anus. 

 The intestine enlarges slightly as it passes backward ; it is wide and 

 straight : is not tied down to the parietės of the body by mesenteric 

 filaments as in the Strongylus gigas, &c. ; its surface is irregular, and it 

 seems to contain a spirai tube or valve, but this appearance arises 

 from the nature of the internal surface of the intestinal tunics, vvhich 

 is beset vvith large regular obtuse lozenge-shaped processes arranged 

 in alternate longitudinal rovvs. 



" The lateral lines of the body consist distinctly of two vessels, 



* yjx6o^maxil!a, moi/.x os. 



