KONGL. SV. VET. AKADEMIRNS IIANDLINGAR. BAND. 21. N:() 5. 



1. TYRO CORNIGERA, H. MILNE EDWARDS, 1830. 



Diag'il, Caput superne carinatum. Antenna primi paris corpore longiores. Pedes pereii primi paris 

 validi, metacarpo filiformi. Dactyli pedum tertii et quarti parium validissimi. Rami 

 externi pedum uri obsoleti. 



The head is keeled on the upper side. The first pair of antennae are longer than the body. 

 The first pair of pereiopoda are strong, with filiform metacarpus. The third and fourth 

 pairs with very strong dactyli. The exterior rami of the uropoda are obsolete. 



Hab. »The Atlantic, captured by Mr Raynaud.). (M. E.). 



Syn. 1830. Hyperia cornigera, H. MILNE EDWARDS. »Extrait de Recherches pour 



servir a l'histoire naturelle 

 des Crustacea amplii- 

 podes». Ann. Sc. Nat. 

 Tome 20 me , p. 387. 



Tyro » » » 1840. Histoire naturelle des Cru- 



staces. Tome 3 me , p. 80. 



» » » Spence Rate. 18G2. Catal. Amph. Crust. Rrit. 



Museum, p. 308. 



» » » C. Bovallitjs. J 887. "Systematical list of the Am- 



phipoda Hyperiidea». Bib. 

 t. K. Sv. Vet. Ak. Handl. 

 Bd. 11. N:o 16, p. 3. 



I have not been able to identify Tyro cornigera with any of the specimens I 

 have examined, but I think that it is closely allied to T. atlantica or T. gracilis. 



H. Milne Edwards has already pointed out the sexual difference, mentioning the 

 long slender four-jointed second pair of antennae in the male, and the rudimentary ones 

 in the female. The characteristic of divergent obtuse keels on the upper side of the head 

 is common to all species I know, being only more or less distinct, and depends upon a 

 median depression caused by the strong development of the basal joints of the first pair 

 of antennae. 



Here follows an extract of the description of Milne Edwards. 



The upper side of the head is provided with two small, obtuse, divergent crests. 



The first pair of antennas are longer than the body; the inner margins feebly ciliated. 



The second pair of antenna? are rudimentary in the female; in the male they consist 

 ol four joints, the last two the longest. 



The first pair of pereiopoda are tolerably robust, the tibia and carpus are elongated, 

 the metacarpus is almost filiform. 



