492 BULLrETIN 15 8, UNITED STATES NATIONAL MUSEUM 



PENNELLA ORTHAGORISCI Wright 



Figure 295, d 



Pennella orthagorisci Weight, Ann. Mag. Nat. Hist., ser. 4, vol. 5, p. 43, pi. 1, 

 1870.— Wilson, Proc. U. S. Nat. Mus., vol. 53, p. 124, 1917. 



Occurrence. — Taken by Kathbun from the flesh of a sunfish cap- 

 tured in Vineyard Sound. 



Distribution. — British Isles (Wright, T. and A. Scott, Norman) ; 

 South Africa (Stebbing) ; North Atlantic (Steenstrup and Liitken, 

 Brian). 



Color. — Head and horns light brown, trunk dark olive-brown, the 

 grooves between the transverse ridges lighter; plumose appendages 

 a deep black; ^^^ strings grayish white. 



Female. — Head wider than long, rarely twice as wide, its lateral 

 margins convex; anterior end flattened and inclined ventrally; pa- 

 pillae numerous and very small, covering not only the end but some 

 of the sides of the head; two horns extending diagonally outward, 

 tapered to a blunt point. Neck shorter and half as wide as the trunk, 

 which is ridged transversely ; abdomen two-fifths as long as trunk, its 

 plumules profusely branched and directed backward. First antennae 

 indistinctly 3-segmented ; second antennae 2-segmented ; intervals be- 

 tween the successive pairs of legs in the proportion of 1:4:4. Total 

 length, 150-200 mm. Egg strings, 125-150 mm. long. 



Remarks. — This species may be identified by the width of the head 

 and the short abdomen. The abdominal plumes are also all turned 

 downward and backward, leaving the dorsal surface of the abdomen 

 uncovered. 



Suborder LERNAEOPODOIDA 



Body of both sexes usually rigidly fused and showing no movable 

 articulation and often no trace of segmentation; with or without 

 dorsal, lateral, or posterior processes. Sexual dimorphism univer- 

 sally present, resulting in great disparity of size between the sexes 

 and a corresponding dissimilarity in structure. Carapace often 

 present, but never any paired dorsal plates as in the Caligoida. 



Proboscis short and blunt, more often lacking; first antennae 

 minute and with only a few segments; second antennae very small, 

 uniramose or biramose, sometimes prehensile. Second maxillae in the 

 female often modified into cylindrical " arms," united at their tips to 

 the pedicel of an attachment bulla. This is the mode of attachment 

 in the type family of the group, the Lernaeopodidae, but many 

 genera have no second maxillae, and sometimes when present they 

 are not prehensile. In genera using this mode of attachment the 

 maxillipeds migrate forward more or less during development and in 

 the adult often stand in front of the second maxillae. The swimming 



