of the Fishery Board for Scotland. 215 



Remarks. — The Notopterophorus described in the preceding notes, 

 though.it does not conform altogether to Hesse's description of Notoptero- 

 phorus papilio, agrees with it in several important particulars, and I am 

 therefore inclined to ascribe it to that species. Moreover, the mouth 

 appendages described and figured here are apparently identical with those 

 of the form recognised as belonging to Hesse's species in Dr. Brady's 

 " Monograph of the Free and Semi-parasitic Copepoda of the British 

 Islands," vol. I., p. 142, plate xxxi.. figs. 3-12. 



The two habitus figures given in M. Hesse's original work and repro- 

 duced in the Monograph referred to are, in respect of the slender form of 

 the cephalo-thorax, unlike any of the specimens I have examined. On 

 the other hand, Hesse's description of the cephalo-thorax and abdomen 

 agrees tolerably well with Scottish specimens of the adult female.* 



Another point of interest which is noticed by Dr. Brady is the great 

 similarity between this species and the members of another genus, and in 

 referring to this he says that " except for the peculiar wing-like dorsal 

 appendages there seems to be little to separate this genus from 

 Doropygus" and this corresponds with the opinions of other observers, 

 and is also supported by the Doropygus-like form of the young female, 

 and still more by the general character of the male. Still, the presence 

 in the adult female of these remarkable appendages is in itself, I think, 

 a sufficient reason for separating this and similar forms under the 

 distinctive name established by Costa and utilised by M, Hesse. 



The purpose which these curious and wing-like expansions serve in the 

 life-history of the creature may be, as M. Hesse suggests, to assist its 

 movements " or to aid in removing obstacles from its path." I am 

 inclined, however, to agree with Dr. Brady, who says — " For my own part 

 I find it difficult to believe that these excessively delicate organs can be 

 of much use for such purposes, or to understand why, if they are so used, 

 they should, be entirely wanting in so many other species which live 

 under the same conditions. We must, I think, admit that their use is at 

 present quite unknown. "t 



I have obtained this Copepod in large Ascidians from various Scottish 

 localities, but nowhere so common as in Ascidians dredged in Scapa 

 Flow, Orkney. The branchial chamber of the large Ascidians dredged 

 there was sometimes crowded with these Copepods. 



Though many specimens have been examined by me from Scottish waters, 

 they were apparently all of the one species, but examples were obtained 

 in different stages of development, from the young females without dorsal 

 appendages, or with a mere indication of them, to those that were adult 

 and whose dorsum was ornamented with the appendages fully expanded. 



In full-grown specimens the ovigerous sac was usually so distended, 

 and the integument so thin and transparent, that through it the eggs or 

 larvae could be seen crowded together. Occasionally examples were 

 observed with the ovigerous sac empty and collapsed, its contents having 

 been set free. 



Herr R. Buchholz has described what appears to be a different species 

 from that of M. Hesse under the name of Notopterophorus elongatus,t 

 which is also referred to by Dr. Giesbrecht in his remarks on the 



* Kef erring to this part of the animal, Hesse says : — " Le thorax est gros et court; il 

 se divise en cinq articles a peu pres de la m£me grandeur, sauf pourtant le dernier que 

 est le double des autres, et que acquiert encore un volume plus considerable a mesure qu 

 'il se remplit d'ceufs, et que ceux-ci se deVeloppement par 1 'incubation." 



t Brady, op. cit., p. 144. 



X " Beitrage zur Kenntniss der innerhalb der Ascidien lebenden parasitischen Crustaceen 

 des Mittelmeeres." Zeitschr. Wiss. Zool., Band 19, p. 127. taf. viii., fig. 6, and taf. ix., 

 fig. 6 (1869). 



