230 Mr. IL A. Baylis on the 



granulated appearance of the spicules. These points are all 

 borne out by the description ; from its larger size, however, 

 and certain differences in the arrangement of the papillae, and 

 in the proportions of various parts of the body, it is evident 

 tiiat the species is distinct from both T. tiara and T. diadema. 



From the features of the type-species, T. tiara, and that 

 now described as T. diadema, it is possible to extract some 

 characters whicii may be regarded as being of generic value, 

 and a revised definition of the genus may be given, somewliat 

 as follows : — 



Tanqua, R. Blanchard, 1904. 

 [= CtenocephaluSy v. Linst., 1904.J 



Gnathostoniidai : of medium size, moderately stout in 

 proportion to the length of the body. Head provided with 

 two lips, dorsal and ventral, each bearing on its iinier side 

 three rounded tooth-like projections. At tlie base of the 

 head there are four rounded submedian cuticular swellings, 

 marked with distinct transverse striations. Anteriorly the 

 lips are twisted slightly out of the middle line, towards oppo- 

 site sides, in such a way that the teeth of one lip can be 

 interlocked with those of the other lip. Cuticle tiiick, with 

 irreguhir transverse wrinkles and exceedingly fine transverse 

 striations. Tlie cuticle of the anterior end may be loose and 

 form a protective sheath, within wiiich the liead can be 

 retracted. CEsophagus rather long, simple in structure, 

 increasing gradually in diameter from before backwards. 

 No oesophageal bulb, oesophageal or intestinal diverticula. 

 Four elongate cervical glands |))esf'nt, opening to the exterior 

 on the basal portion of the head. Tail of male provided 

 with more or less pronounced lateral aljB near the tip, giving 

 it a lancet-shaped outline, and having eight pairs of elongate 

 papillae of different sizes, some of which have a characteristic 

 swelling near the middle. Copulatory spicules curved, 

 cylindrical, and armed throughout with minute spines. Pos- 

 terior end of the body, in the male, provided with a series of 

 oblique muscle-bands on either side of the ventral surface, 

 extending for some distance in front of the anus. Tail of 

 female short, tapering and pointed. Vulva in the posterior 

 half of the body. Vagina rather short, with a coat of circular 

 muscles ; giving off two wide uterine branches, one of which, 

 with its ovary, lies anteriorly, the other posteriorly, to the 

 vagina. Eggs oval, with thin shells, ornamented with fine 

 granulations. 



Type-species, T. tiara (v. Linst.), 1879. 



