NO. 1573. PARASirW COPEPODS—WILSOX. 443 



2^us, and Lepido^msV Not being able to answer the question defi- 

 nitely, they concluded to classify all male forms as ^^ Nogagus^^ species, 

 while the females were placed in the other genera. They then divided 

 the '^ Nogagus'^ forms into two groups and the same division was 

 subsequently adopted by Gerstaecker in Broun 's Thierreich. In the 

 latter publication Gerstaecker even names his second subfamily after 

 this genus, calling it the Nogagina. The two groups as given by 

 Steenstrup and Tiitken are: A, those having the fourth legs biramose, 

 the rami two-jointed, and the "tail" (abdomen) two-jointed; B, those 

 having the fourth legs biramose, the rami one-jointed, and the "tail" 

 also one-jointed. 



A comparison of the data given on the following pages will show 

 that tJiis was really the first step toward a separation of the different 

 genera included in tins imaginary genus, lender the first group (A) 

 would come the males of Pamlarus, Echthrogalfus, and Dinematura, 

 while in the second group (B) would be included the males of Nesipjms 

 and Perissopus. But there are two genera which were not included 

 in either group, Demoleus, which belongs in the first group and is the 

 largest of all the Nogaus forms, and Gangliopus, in the males of which 

 the abdomen is two-jointed, but the rami of t!ie fourth legs have only 

 a single joint. 



Gerstaecker reverses the order of the two groups and says nothing 

 about the joints of the abdomen. 



Steenstrup and Liitken and Heller place the ^' Nogagus'' species 

 under the Pandarinae; Gerstaecker niakes of them a third subfamily, 

 distinct from both the Caliginae and Pandarinae, calls it, as noted 

 above, the Nogagina, and includes in it along with '' Nogagus'' the 

 genera Nesippus, Demoleus, Dysgainus, Euryphonis, Trehius, Elytro- 

 pliora, Alehion, Dinematura, and Echthrogaleus. 



Most other writers place the Nogaus forms under the Caligina^, even 

 so recent a writer as Bassett-Smith (1899) putting them there. That 

 they really belong with the Pandarinae was well argued by Hesse in 

 1883, who gave the following reasons for such a classification: (1) The 

 grooves separating the areas on the dorsal surface of the carapace are 

 not like those in the Caliginse. This is due to the fact that (2) only 

 one thorax segment is fused with the head, all the others being free, 

 while in the Caliginae three of the segments are fused with the head 

 and only one is free. (3) The anal laminae are larger and flatter than 

 those in the Caligim^, and are similar to those m the Pandarinae. 

 (4) The eyes are not fused on the mid-line, but are separated after the 

 manner of the Pandarinae, and there is a third eye similar to that in 

 many of the latter. (5) There are no lunules, furca, nor first maxillae. 

 (6) The mouth-tube is elongated and narrow-conical, terminating in a 

 lanceolate point exactly like that of Pandarus, but very different from 

 the short and wide tube of the Caliginae, which is blunth^ rounded at 



