366 Transactions. — Zoology. 



The first foot-jaws are of remarkable shape, and I have 

 figured one of them. They are 3-jointed ; the basal jomt is 

 stout and strong ; the 2nd jomt is elongated, flattened, and 

 flanged on the inner side, and produced at the distal end into 

 a pointed knob, round the extremity is a line of short spines 

 surrounding it like a collar ; the last joint is in the form of a 

 round knob obliquely striated in a longitudinal direction, and 

 having two lines of short spines which converge at its 

 extremity. I cannot suggest the origin of this remarkable 

 development, or its present use. 



Hah. Numerous specimens taken from the upper jaw of a 

 porbeagle shark — Lamna cornuhica (Otago Museum). Also a 

 number from the same kind of shark taken at Napier by A. 

 Hamilton. According to Gould this species has been taken 

 on the mackerel-shark — Lamna punctata — on the coast of 

 Massachusetts, U.S.A. 



Genus Lernanthropus, Blainville. 



The animals of this genus are chiefly remarkable for the 

 abnormal development of the third and especially of the 

 fourth pair of thoracic feet, which are produced into the form 

 of cylindrical or lamellate appendages under the body. The 

 first and second pairs are very small. The anterior antennai 

 are very small, while the second pair are developed into 

 hooked claws by which the animals attach themselves to their 

 host. 



Owing to the very varying extent to which the parts of the 

 thorax are developed, there is great diversity of form among 

 the different species. 



1. Lcrnanthrojms pcrcis, n. sp. Plate XXVII. , fig. 2, a-j. 



Female. — The whole body of this species is about one and 

 a half times as long as it is broad. Seen from above, the 

 head is somewhat distinctly separated from the thorax, and is 

 about subquadrate m form : its lateral margins are slightly 

 (hlated into two rounded lobes. The thoracic portion is 

 broadly winged, the first segment showing a shoulder-like 

 protuberance on each side, and the second being produced 

 backwards into acute angles. The dorsal shield is about as 

 broad as the thorax, about half as long as the whole body, 

 rounded behind, and with a slight notch in the middle of the 

 posterior margin. 



Seen from below, two-thirds of the lower surface is covered 

 by the large lamella of the third pair of legs, which do not, 

 however, reach quite to the extremity of the dorsal shield, 

 but leave exposed the folded-up ends of the oviferous tubes. 

 Genital segment very short. Abdomen short, thick, rounded, 

 and fleshy, veiy indistinctly 2-jointed ('?), with a small notch 



