272 MR. H. A. BAYLIS AXD LT.-COL. CLAYTOX LANE ON 



completeness. It is quite uncertain to what genus it belongs, 

 but if Rudolphi's account of the head -bulb is correct it seems to 

 approach more nearly to Tcmqua than to any other. On the 

 other hand, its host (a fish) and its habitat (the spiral valve of 

 the intestine) suggest very strongly that it may have been an 

 Echinocephalus ((/.v., p. 273). Rudolphi distinctly states, how- 

 ever, that the head-bulb is transversely striated and composed of 

 two hemispheres, and he makes no mention of any armature 

 of hooks or spines. 



The species is briefly diagnosed as follows : — 



" Ascaris : memhrana capitis utrinqae seDiiorhiculari, striata ; 

 Cauda ohtusiuscida." 



The following is a rough paraphrase of the further account 

 (originall}^ in Latin) of the worm, which was found in the lower 

 part of the intestine of the Sturgeon, Acipenser stario, in the 

 spiral valve. 



Worms an inch long, slender, white. Head spherical to naked 

 eye, separated from the body by a constriction, and infiexed. 

 Under the microscope a hemispherical membrane is seen on 

 either side, transversely striated, giving the head a spherical 

 shape. Mouth small, surrounded by three large, bluntly conical 

 lips, joined at the apex, but not at the base, by lateral membranes, 

 "so that they become obscured." Body smooth, attenuated at 

 both ends, more so anteriorly. Tail rather blunt. Lips of vulva 

 prominent, in third quarter of body. Alimentary canal like that 

 of Ascarids. Eggs very peculiar, greatly elongated, blunt-ended 

 (oblong-elliptical), clear at one end. 



Rudolphi says (as we understand him) that on account of the 

 genei-al shape of the body and of the lips the worm belongs to 

 the " Ascarides," but that the arrangement and " obscuring'' of 

 the lips [sc. by the " membrane " referred to] and the peculiar 

 eggs mark it ofi' as something different. Hi.s description suggests 

 that the " three lips " he saw were the three tooth-bearing lobes 

 of one lip, seen from the side by transparency, and the " mem- 

 brane " joining them at the apex the cuticle of the outer or more 

 lateral portion of the lip. 



Physaloptera constricta Leidy, 1856. 



Leidy (1856, p. 53). 



" Body Avhite, Avith the brown intestine shining through, 

 cylindrical to within a short distance of the extremities, incurved ; 

 anterior extremity with one or two constrictions, and abruptly 

 infiexed. Lips large, lateral, constiicted from the body, each 

 trilobate. Tail of female incurved, abruptly conical and acute ; 

 of the male alated, with the alfe narrow, long, and turgid. 

 Length of female 1| inches, breadth two-fifths of a line; male 

 half the size. 



" Found frequently in the stomach of Tropidoiwtics sipedon, 

 with the anterior extremity of the body hooked through the 



