394 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 09 



LicJiomoIgus (part) T. Scott, 1892, pp. 266-267.— T. and A. Scott, 1892, pp. 201- 



203.— Hekdman, 1893, pp. 8:3, 135.— Thompson, 1893, pp. 177, 207-208. 

 Pseudolichomol[/us Thompson, 1897, cited iu Herdman, 1897, p. 87 (type, P. 



columbiae Thompson, 1897). — Wilson, 1932, p. 591. 

 Pseudolichonwlgus Pesta {not Thompson), 1909, pp. 263-265 (type, P. pectinis 



Pesta, 1909).— Pelseneeb, 1929, pp. 35, 44. 

 PestaUchomolgus Wilson, 1932, p. 587 (new name for Pseudolichomolgus Pesta; 



type, P. pectinis (Pesta, 1909) ). 



Diagnosis. — Body shape cyclopoid. Segmentation somewhat vari- 

 able; metasome 4- or 5-segmented; urosome of female 5-segmented, 

 that of male 6-segmented. Rostrum well developed with obvious pre- 

 hensile function. Antennule 7-segmented. Antenna of four seg- 

 ments, second always longest. Labrum deeply divided in the midline. 

 Mandible constructed on simplest lichomolgid type, elongated, with 

 tapering flat blade arising from a fairly stoutly chitinized base, with 

 no articulation. Edges of mandible serrate, finely dentate or ciliate. 

 Maxillule, inserted directly on head rather than on mandible, consists 

 of flat palplike appendage ; terminal armature various, comprising two 

 or three setae. Maxilla 2-segmented, base very large and conspicuous. 

 Two setae typically present on second segment, the more distal usually 

 with a row of spinules or cilia on its medial margin ; proximal seta not 

 thus ornamented. Maxilliped of female considerabl}^ reduced, its 

 segmentation varying among the species. Terminal podomere a 

 pointed, spinelike segment, or bluntly rounded. Male maxilliped 

 3-jointed, prehensile. Swimming legs all biramous, trimerous, with 

 characteristic modification of fourth endopodite. Fifth leg a single 

 free segment, base represented only by a slight expansion of the body 

 proper, basal seta present, borne on dorsal side of appropriate body 

 segment. Armature of free segment two members, usually a conspicu- 

 ously heavy spine and a seta. 



Genotype. — Paranthessiud anemoniae Claus. 



Remarks. — ^The wide definition of Paranthessius as here offered pre- 

 sents some difficulties in the possibility of inclusion of ModioUcola 

 Aurivillius and SabelUphilus Sars. The latter genus stands fairly 

 well alone by virtue of the following characters : The rostrum (bifid) ; 

 the antennule (proximal two segments expanded) ; the antenna (pre- 

 hensile hooks on both third and fourth segments) ; and the ornamenta- 

 tion of the maxilla (fairly spinous) . Its remaining appendages would 

 fit with no difficulties in the normal variations of the species of Paran- 

 thessius. Many years of usage make it most desirable to retain the 

 generic distinction. ModioUcola presents even less strong separation, 

 and it is possible that a further broadening of the definition of Paran- 

 thessius to include the forms now placed in ModioUcola may become 

 d;esirable. However, as I am convinced that the number of un- 

 described species of lichomolgids is greater than the number now 



