104 MESSES, E. W. L. HOLT AXD W. M. TATTEESALL— BISCAYA^' PLANKTON : 



We have examined tlie whole of the Scliizopods collected hy Dr. Fowler, who has 

 attempted to sort out every specimen from even the largest gatherings, for fear that our 

 preliminary results, based upon samples, might not truly express the facts of vertical 

 distribution. We found, however, that the conclusions deduced from examination of the 

 material taken from the first half of a large gathering were not disturbed by the over- 

 haul of the remainder, and imagine that this will probably hold good for other plankton 

 collections, except in regard to organisms which are so small that their distribution in 

 store-bottles is determined by considerations of 'gravity. 



The collection naturally included a large number of ova and larvae, the distribution of 

 which is of undoubted importance, hut in this communication we name only the 

 larvse of a few species which happen to be absolutely determinable. The remainder 

 are reserved for a further note, in which, with the aid of a large collection from the 

 West of Ireland (a region practically identical in specific Schizopod fauna with the 

 Biscayan region), we hope to be able to add materially to the knowledge of the young 

 stages. 



Our report deals, therefore, only with specimens which have or have nearly assumed 

 the adult form, or which, if larval, are exempt from the possibility of confusion with the 

 larvae of species other than those to which we have assigned them. 



When the collection was placed in our hands, we were engaged in the study of similar 

 forms taken from deep water off the West Coast of Ireland, and, with Dr. Fowler's 

 permission, we have included in the Irish paper * such systematic notice as was required 

 by the Biscay material, with some general remarks on the horizontal and vertical 

 distribution of all the species determined. 



Only one form, a Mysid of the genus Enchcetomera, is new to science. We have 

 named it in honoiu* of its discoverer, and, as aj)pears from the figure, it is rather closely 

 allied to E. tenuis, G. O. Sars, from the S. Pacific. Its range as at present known 

 includes Bay of Biscay {' Research'), W. of Ireland {' Helga'), Atlantic 31° 06' N., 

 24° 06' 45" W. {Hansen), and Mediterranean (as E. tenuis, Lo Bianco). 



For general convenience, we reprint here our diagnosis of the species : — 



EucH^TOHEKA FowLEEi, Holt & Tattcrsall t. (Text-figure.) 



Form slender. Inteyuments thin and diaphanous. Carapace with the anterior margin 

 forming a very obtuse angle in the rostral region, its apex considerably posterior to the 

 origin of the peduncles of the eyes ; its posterior margin not deeply emarginate. Eyes 

 large, closely apposed, sub-rhomb oidal and slightly bilobate, their functional facets 

 confined to an anterior part with long retinal elements, and a postero-lateral part with 

 short retinal elements; these parts deeply pigmented, the pigment dark brown after 

 preservation, the remainder of the eye being pale brown, with facets vestigial and 

 probably functiouless. Antennular ])^duncle with the basal joint about one and a half 

 times as long as the eye, distal joint as long as the two preceding; male appendage 



* " Schizopodous Crustacea from the Xorth-East Atlantic Slope." Report of Sea and Inland Fisheries, Ireland, 

 for 1902 and 1903, pt. ii. Appendix Xo. IV. 

 t lUd. p. 123, pi. sxiv. figs. 1-3. 



