142 BULLETIN OF THE BUREAU OF FISHERIES. 



Predominantly southern forms. 



Pagurus pollicaris Cape Cod Bay to South Carolina. 



Pagurus longi carpus Cape Ann, Mass., to Texas. 



Pagurus annulipes Nantucket Sound to Florida. 



Pelia mutica Vineyard Sound to West Florida. 



Libinia emarginata Casco Bay to West Florida. 



Ovalipes ocellatus Provincetown to the Gulf of Mexico. 



Neopanope texana sayi Provincetown to East Florida. 



Pinnotheres maculatus Cape Cod to Texas. 



Of approximately equal range north and south. 



Crago septemspinosus East Florida; Arctic Alaska. 



Cancer irroratus Labrador to South Carolina. 



Cancer borealis From Nova Scotia to deep water off South Carolina. 



Thus, as in the case of the Annulata and indeed of the majority of other groups, the 

 commoner local Decapoda are predominantly southward ranging species, while only two 

 of them are to be regarded as predominantly northern. Of these two, indeed, one is 

 only doubtfully so classified, while both of them occur far to the southward of the Woods 

 Hole region. The inclusion of various stragglers, both from the north and south, would, 

 of course, increase both lists, but much the same proportions would probably be main- 

 tained. 



IX. XIPHOSURA. 



This order has been established to include the genus Limulus, a group of organisms 

 having both crustacean and arachnidan affinities. Limulus polyphemus, our only 

 American species, was very seldom taken during the survey dredgings, being primarily 

 a shallow-water animal. With respect to its distribution, it is predominantly a south- 

 ward-ranging form, occurring, according to Verrill, from Casco Bay to Florida. It has 

 not been recorded for Canadian waters. 



X. PYCNOGONIDA. 



Of the sea spiders only 6 species appear in our catalogue, and of these 6 one is per- 

 haps extralimital. Our knowledge of the New England species is due in large measure 

 to the labors of E. B. Wilson, supplemented recently by the studies of L. J. Cole. 



Only two of the species (Tanystylum orbicular e and Anoplodactylus lentus) appear 

 with any frequency in the dredging records. The local distributions of these two species, 

 so far as these are shown by our dredgings, are represented in charts 120 and 121. Both 

 species are seen to be confined almost exclusively to Vineyard Sound, and both (partic- 

 ularly Anoplodactylus) appear to be restricted to the eastern half of the Sound. One 

 might reasonably expect to find a more exact correlation between the distribution of 

 these species and the distribution of the hydroids among which they live. But little 

 correlation is to be observed, so far as ou* charts go. 



The smaller and less conspicuous of these two pycnogonids {Tanystylum orbicu- 

 lare) was probably frequently overlooked in listing the contents of the dredge, and it is 

 likely, therefore, that this species is of more frequent occurrence than appears from 

 our records. Its distribution, likewise, may be somewhat more general. 



This class is represented in our list by a smaller number of species than have been 

 recorded for any of the other stations considered in our comparative table. To what 



"■ Except Trieste, where apparently no record has been kept of the Pycnogonida. 



