1 1 



between Valentia in Ireland and die Faröe banks, and gave a characteristic figure. This genus is 

 distinguished from Calanus, by the presence of a remarkable hook on the anterior surface of 

 the second joint of the basiopodite of the first feet, and by the last joint of the exopodites of 

 the second, third, and fourth feet being furnished with three spines on the outer margin, instead 

 of two as in Calanus. Wolfenden fully described his genus in 1905, in Plankton Studies, part 1. 

 Sars in the same year (1905 a) described a very similar form under the name of Macrocalanus 

 lougicoruis, and a good deal of confusion arose through no figures accompanying the description. 

 Sars, however, in 1907^), withdrew his genus in favour of the one named by Wolfenden, which 

 had the prior claim. Wolfenden in his first description had then only met with one form, to 

 which he gave the name Megacalanus princeps. In Plankton Studies, part I, the number of species 

 under Megacalanus was increased to two. The specific name princeps originally adopted for the 

 type of the genus was dropped in favour of a new specific name, bradyi, while the name princeps 

 was applied to the additional form, which is clearly not a Megacalanus. There is no doubt, 

 that Megacalanus bradyi is the same form for which the genus was founded in 1904, as it is 

 characterised by the prominent hook on the second basal joint of the first feet and the figure 2, 

 plate I, is identical with the figure given with the original description in 1904. The second 

 species of the genus, was identified as equal to Brady's Calanus princeps of the Challenger 

 report, and the basiopodite of the first pair of feet is described as having no tracé of hooks. 



In the interval between the publication of Wolfenden's two papers Sars had recorded 

 the occurrence of Macrocalanus princeps {Calanus princeps Brady). 



In Plankton Studies, part II, 1906, Wolfenden has the following note: "Professor G. O. 

 "Sars has informed me that the genus Megacalanus (Wolfenden) is identical with his genus 

 "■Macrocalanus (Sars) (Buil. du Musée Océanog. de Monaco), and Megacalanus Bradyi is the 

 "same as his species Macrocalanus longicornis, and that my name, Megacalanus, however has 

 "the priority over Macrocalan?is. He also informs me that the species described by me as 

 " Megacalanus princeps = Calanus princeps (Brady) is not that species, but = Bathycalanus 

 " Richardi (G. O. Sars), and that Brady's Calanus princeps is a true Megacalanus, differing 

 "from M. longicornis (G. O. S.) = Megacal. Bradyi (Wolfenden), in the strongly recurved frontal 

 "appendages, somewhat shorter Anterior Antennae, and the dense ciliation of the spines on the 

 "Anterior Maxillipedes, which otherwise are quite normal in appearance. 



"The genus Bathycalanus differs from Megacalanus in the peculiar armature of the 

 "frontal part and in the somewhat different structure of the maxillae and maxillipedes (both 

 "pairs), and in the structure of the first pair of feet, which are without the hooked process of 

 "the second basal, and have the outer ramus composed of only two joints". 



It is quite certain that Wolfenden's second species, Megacalanus princeps (Brady), is 

 not a Bathycalanus, because Wolfenden in his description of the species states that the first 

 four pairs of feet have three-jointed rami. Wolfenden, after an examination of the dissections 

 of Calanus princeps preserved in the British Museum, concludes that Brady's species is neither 

 a Megacalanus nor a Bathycalanus, vet he finally renames Megacalanus princeps Wolfenden, 

 not the original one which established the genus in 1904, as Bathycalanus maximus. 



Sars 1905(0), and Farran 1908, identify Brady's Calanus princeps with the genus 



