. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. LARVAE OF DECAPOD CRUSTACEA 435 Antenna with segment 2 greatly expanded, flagellum extending beyond antennule. Maxilla with exopod expanded and reaching behind maxillipede i, but without setae. Maxillipede i with epipod. Maxillipedes 2 and 3 with rudimentary exopods, without setae. Legs without coxal spines. Leg 5 with small bud representing exopod. Gills present. Pleopods and uropods large; no spines dorsally on abdominal somite 6. It is naturally impossible to identify this Phyllosoma; but it
. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. LARVAE OF DECAPOD CRUSTACEA 435 Antenna with segment 2 greatly expanded, flagellum extending beyond antennule. Maxilla with exopod expanded and reaching behind maxillipede i, but without setae. Maxillipede i with epipod. Maxillipedes 2 and 3 with rudimentary exopods, without setae. Legs without coxal spines. Leg 5 with small bud representing exopod. Gills present. Pleopods and uropods large; no spines dorsally on abdominal somite 6. It is naturally impossible to identify this Phyllosoma; but it is evidently closely related to a form described by Stephensen (1923, p. 77) and referred by him to Themis orientalis. The Discovery specimens do not seem to belong to the same species, as Stephensen's figures show strong coxal spines on legs 1-3. Santucci (1926) has de- scribed a larva of 30 mm., also from the Mediterranean, which appears to belong to the same species as my specimens, and this larva he supposes also to belong to Themis orientalis. There are great difficulties in accepting such an identification. In the first place T. oricjitalis is the only species of the genus known, and it is confined to the Indo-Paci- fic region, with the exception of a doubtful record from the Adriatic, and one from Natal (Von Bonde). It seems unlikely that it would have been overlooked in the Atlantic if it is as common as these larvae would show it to be. It is also evident that there must be two distinct species in the Mediterranean of the genus to which these larvae belong. At the same time, our knowledge of the distribution of adult Decapoda is not so exhaustive that such an argument can have much weight. If we knew only the Phyllosomas of Pali- nurus and ScyUarus this Phyllosoma would certainly be regarded as a Palinurid; but it appears that the differences between these two genera cannot be taken as valid for their families. We have already seen that the absence of an exopod from th
Size: 1358px × 1841px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, booksubjectocean, booksubjectscientificexpediti
