1892.] NATURAL SCIENCES OF PHILADELPHIA. 148 



Abdomen clavate, truncated at its extremity, slightly swollen in 

 the middle. 



Legs stout ; first or basal joint bi'oad, rather broader antero-pos-, 

 teriorly than the lateral processes of the segments, with the appear- 

 ance of a dorsal notch on its outer edge due to the close approxima- 

 tion of two dorsal tubercles ; second joint rather smaller than the 

 first ; third rather smaller than the second ; the three joints together 

 in the third ambulatory leg about as long as the proboscis ; fourth 

 strongly developed, about two-thirds of the length of the proboscis 

 proximal half of the ventral surface considerably swollen, and a 

 single rather weakly developed dorsal tubercle at its distal extrem- 

 ity ; fifth about equal in length to the fourth, but more slender; 

 sixth rather shorter than the fifth ; seventh very short, sub-triangu- 

 lar ; eighth about as long as the sixth ; ninth about two-fifths of the 

 eighth. Fifth, sixth and eighth joints Avithout tubercles ; two or 

 three bristles upon the distal dorsal surface of the sixth ; a few fine 

 hairs upon the ventral surface of the seventh, and a few bristles 

 upon ventral surface of the eighth. No auxiliary claws. 



Color in alcohol, yellowish-brown. 



Length of body of the largest of the five specimens, from the ex- 

 tremity of the proboscis to the extremity of the abdomen, H mm. 



Three of the type specimens have been given by Mr. Stearns to 

 the museum of the Academv and two of them are in his own col- 

 lection. 



This species appears to be mostly nearly allied to Pycnogonum 

 I'Utorale Strom, differing from it among other characters, however, 

 markedly in the shape of the proboscis, which in the latter species is 

 conical, and in Pycnogonum Stearnsi sub-cylindrical. 



A list of the species o^ Pycnogonum hitherto known is appended.^ 



P. littorale Strom. 



Coasts of the North Atlantic ocean and adjacent seas.^ 



^In this list Astridium (^Pycnogonuvi) orientale Dana, from Balabac Strait (U. 

 S. Expl. Exped., vol. xiii, p. 1391, pi. 96, figs. 2 a, b, c,) has not been included, 

 as it probably represents a distinct genus. 



^Philippi's (Archiv. f. Naturg., 1843, ix Jahrg. p. 175) record of this species from 

 Naples I consider to be exceedingly doubtful, as Professor Dohrn did not find it 

 there. Philippi probably mistook one of the two species described from that place 

 by Professor Dohrn for this species. I am also very skeptical in regard to the 

 species described under this name from Chili by Nicolet (Gay's Historia fisica y 

 politica de Chili, Zool., T. Ill, p. 308; Atlas, pi. IV, fig. 8). If a species of 

 Pycnogonutn is found on the coast of Chili it is almost absolutely certain that it 

 is not P. littorale. If the figure given by Nicolet is correct, it must be a species 

 distinct from P. littorale. 



