15 



dark brown colour and there is a small spot of black pigment on the lower side of the peduncle 

 near the middle of the outer margin; in the specimens from Stat. 178 the cornea shows a 

 much paler, reddish colour, the small spot of black pigment is present and is, in the female, 

 even quite distinct on the upper side of the peduncle. 



The thickened basal part of the upper antennular flagellum appears in the male from 

 Stat. 178 just as long as the distance between the tip of the rostrum and the posterior extremity 

 of the post-rostral carina, at the cervical groove, viz. 1 i mm.; the rest of the flagella are lost. 

 Antennal scale narrow, pointed. 



Remarks. Benthesicymtis Tanneri Fax. from the Galapagos is closely related, but 

 differs by the post-rostral carina extending farther backward, by the different form of the thelycum, 

 by the broader antennal scales and by the post-cervical groove reaching less far upward (though 

 in the coloured hgure of Faxon's paper it attains the median line of the carapace); the petasma 

 is also different, like the shape of the eye-peduncles and the antero-lateral angle of the carapace 

 is acute, while in Benth. Investigatoris it is rounded. 



General dis tr i b u t i o n : Andaman Sea (Alcock) ; Gulf of Manar (Alcock); off Saya 

 de Malha (Borradailej; Hawaiian Lslands (Rathbun). 



Gennadas Sp. Bate. 



The general distribution of the 1 5 species of the genus Gennadas^ that are at present 

 known, is the following. Two species have a very wide range : Genn. carinatus S. I. Smith 

 that occurs along the east coast of the United States, has also been observed in the Arabian 

 Sea, near the Laccadive lslands, and Gcnn. smtaücs Bouv., a species of which a single adult 

 female was captured between the Azores and New Foundland, but which perhaps also inhabits 

 the Caribbean Sea, should also occur in the North Pacific (vide Stanley Kemp. in : Proc. Zool. 

 Soc. London, 1909, p. 727). Six species are known to occur in the Atlantic, five of which 

 are recorded from various parts of the North Atlantic, namely Genn. Alicei Bouv., Gcnn. 

 ( Amalopenacus) elega^is S. I. Smith, Gcnn. Talismani Bouv., Genn. Tinayrei Bouv. and Ge7in. 

 valens S. I. Smith, a species probably also appertaining to the genus or subgenus Amalopenaeus 

 S. I. Smith; Genn. elegans occurs also in the Mediterranean. A sixth species, Genn. intermedms 

 Sp. Bate, has been observed off Sierra Leone and off Pernambuco. 



The seven other species are exclusively inhabitants of the Indopacific and their distri- 

 bution appears rather limited. Genn. borealis Rathb. has been recorded from the Aleutians and 

 from Kamchatka, Genn. propinquus Rathb. is found along the coasts of the Hawaiian lslands, 

 while two species, viz. Genn. Cabiiani Kemp and Gcnn. parvus Sp. Bate have been taken 

 South of Japan. 



The two species obtained by the "Siboga" are new to science, but the East Indian 

 Archipelago is moreover inhabited by a third, viz. Genn. Boiroieri Kemp, described in 1909 

 and observed West of Manila and North of New Guinea. Besides Gcnn. carinatus still another 

 species has been recorded by Alcock from the Bay of Bengal and the Arabian Sea, under 

 the name of Gcnn. parvus, but it appears to me probable that this species is not identical 



