436 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



Genus PSEUDOCHONDRAC ANTHUS, new. 



Diagnosis. — Head distinctly separated from the rest of the body 

 and covered dorsally with a small carapace. First thorax segment 

 only free, the others fused into the elongate genital portion, which is 

 without any traces of segmentation. Abdomen small and two- 

 jointed. Egg strings long; eggs multiseriate. Second antenna? in 

 the form of stout falcate hooks. Mouth parts at the posterior margin 

 of the head. Mandibles similar to those of Chondr acanthus. Max- 

 illae sickle-shaped laminae like the mandibles, armed with a row of 

 broad blunt teeth along either margin, and carrying at the base on 

 the dorsal surface a blade-like palp. Maxillipeds relatively very 

 large and attached to the extreme lateral margins of the head; 

 their basal joints are flattened lamina?, strongly muscular and bor- 

 dered by muscular flaps on either side; their terminal joints are 

 bilobed, one lobe armed with a stout claw, the other covered with 

 short spines. 



When closed these organs cover the bases of the other mouth parts 

 and the entire sides of the face, giving to the latter a swollen appear- 

 ance; when open they expose the front of the face to its extreme lat- 

 eral margins. There is but a single pair of rudimentary swimming 

 legs, flattened and bilobed at their tips. 



Type-species. — Pseudochondracanthus diceraus. 



{pseudo, and Chondr acanthus.) 



PSEUDOCHONDRACANTHUS DICERAUS, new species. 

 Plate LXVII. 



Host and record of specimens. — Two females with fully developed 

 egg strings, and each with a male attached to its abdomen, were taken 

 from a species of puffer at La Jolla, California, by Doctor McClendon 

 and are Cat. No. 38581, U.S.N.M. (See also p. 477.) 



It has been found on the Atlantic coast as well as the Pacific; a 

 fine lot of specimens were obtained from the gills of the common 

 puffer, Sphceroides maculatus,.bj Doctor McClendon at Woods Hole, 

 Massachusetts, in 1906, and these have been made the types of the 

 species; they are Cat, No. 38603, U.S.N.M. 



Another lot, Cat. No. 38004, U.S.N.M., was obtained from the same 

 fish by Doctor Linton, also at Woods Hole. 



The author was fortunate enough to obtain some living specimens 

 while at Beaufort, North Carolina, in the summer of 1905. 



Female. — General body form short and plump; head as long as i 

 wide, the anterior margin convex, the lateral and posterior margins 

 concave, all four corners projecting and well rounded. From each 

 anterior corner a short and bluntly rounded horn extends out later- 



