136 Messrs. Brady and Robertson on Marine 



male is only two-jointed. Longest tail-seta about as long as 

 the body of the animal. Length -^ of an inch. 



T. Mbernica was taken in no very great numbers in the 

 surface-net in Westport Bay. Anatomically it bears a very 

 close resemblance to, and we have some doubt whether it ought 

 not to be considered as a variety of, the following species. It 

 is, however, very much more slender in all its parts, has not 

 the same tough leathery skin, the same vivid colouring, nor 

 the gibbous outline. That it is not a young form of T. longi- 

 mana is proved by many of the female specimens bearing fully 

 formed ovisacs. 



5. Thalestris longimana, Claus. 

 Valentia Harbour and Killybegs (Mr. E. C. Davison) . 



Genus Parathalestris, nov. gen. 

 Generi antecedenti similis ; pedum vero secundi paris rami interni 

 biarticulati ; mandibulse parva3, tenues, palpo tenui elongato, 

 ramo seeundario minuto, ramo majore setis longis numerosis fim- 

 briate 



Parathalestris Clausii (Norman). 

 Thalestris Clausii, Norman, Last Shetland Dredging Report, p. 297. 

 On weeds in Birtirbuy, Clifden, and Westport Bays. 



We here follow M. Boeck in restricting the generic name 

 Thalestris to those species of Claus's genus which have both 

 branches of all the swimming-feet three-jointed, and the mouth- 

 apparatus constructed as in T. mysis and harpactoides. The 

 second pair of feet and the mandibles in the present species do 

 not fulfil these conditions. 



Genus Dactylopus, Claus. 



1. Dactylopus Stromii (Baird). 



On weeds in Ventry Bay, Valentia Harbour, and Killybegs. 



2. Dactylopus tisboides, Claus. 



In pools near Clifden, and taken in the surface-net in West- 

 port Bay ; moderately abundant. 



3. Dactylopus (?) cinctus, Claus. 



Taken in the surface-net in Westport Bay ; only four or 

 five specimens, all males. 



4. Dactylopus (?) minutus, Claus. 



In the same locality as the preceding species ; scarce. 



