COLE : PYCNOGONIDA. 187 



same. Since they come from such widely separated localities, however, it seems 

 better to let the matter stand as it is, at least until specimens of the two can be 

 compared directly. Furthermore, although Hoek (1881, p. 147) is of the opinion 

 that A. (=Scaeorhy>ichus) armatus (Wilson) l is distinct, I think there can be no 

 doubt that it approaches very closely to the species discussed above. We know 

 far too little about the range of variation during growth and in different individuals 

 to base very positive conclusions upon a few specimens. 



Colossendeis gigas Hoek. 



PI. 1, fig. 3; pis. 3, 7. 



Colossendeis gigas Hoek, Challenger Reports, 3, pt. 10, Pyenogonida, 1881, p. 61- 



64, pi. S, figs. 1, 2; pi. 10, figs. 1-5. 

 Colossendeis gigas Schimkewitsch, Bull. Mus. Comp. Zool., 25, 1893, p. 29, 30. 



One small immature specimen; Station 4672; Nov. 21, 1904; lat. 13° 11.6' 

 S. ; long. 7S° 18.3' W. (off Callao, Peru) ; depth 2845 fathoms; bottom, fine 

 green clay, iufusorian earth full of Diatoms. 



This specimen, though small, agrees very closely with the description of C. 

 gigas given by Hoek. 



Schimkewitsch considered C. gigas Hoek to be specifically identical with C. 

 colossea Wilson (1881, p. 244). That being the case he should have employed 

 the latter name for the species instead of the former, since Wilson's description 

 has priority of publication. Hoek himself (1881, p. 147) noted the resemblance 

 of the two and suggested that they might be identical. Loman (1908, p. 21) dis- 

 cusses the question and is of the opinion that they may be local varieties of a 

 widely distributed deep-sea species. I have compared C colossea from the North 

 Atlantic with the two specimens taken upon the " Albatross " Expedition of 1891 

 and reported upon by Schimkewitsch (1893), as well as with the small specimen 

 taken in 1904. The most constant difference appears to be in the proportion of 

 the legs, which are about five times the length of the body (including proboscis 

 and caudal segment) in the Atlantic specimens, and only four times the length of 

 the body in those from the Pacific. Furthermore, the first tibial joint is about 

 equal in length to the femur in the former, whereas it is shorter (by about the 

 length of the third coxal joint) in the latter. There may be other minor differ- 

 ences, but it is difficult to determine their constancy from a small series of speci- 

 mens. In the characters mentioned the Gulf of Panama specimens agree more 

 closely with the description of C gigas Hoek than do the North Atlantic speci- 

 mens. For this reason I have retained the name of that species and referred 

 them to it, thus following the course of other recent authors in leaving it distinct 

 from C. colossea, though I have little doubt that future collections will reveal 

 i!iter£rradin£r forms, making it necessary to reduce C gioas to subsnecific rank. 



i Wilson (1881, p. 248). 



