From Papers read by 



MAJOR MTJIfN AXD MR. HORSNAILL, 

 At Duver, on Tuesdai/, February 9, 1869. ,,« 



BY MR. HORSISTAILL. 



" On a Crustacean of the Family Pycnogonidaa 

 found in the locality." 



In the course of his interesting essay, Mr. Horsnaill said: 

 —At first sight they might be taUea for diminutive speci- 

 mens of some of the long-legged spider crabs, Inachus or 

 Stenoryuchus ; to the latter genus especially their gaunt and 

 skeletonlike aspect as they lazily sprawl their eight un- 

 wieldy legs over the weeds, gives them a very considerable 

 resemblance. This resemblance is, however, only in exter- 

 nal form — for while the crabs, and their congeners the 

 shrimps, prawns, and lobsters, arc the most highly organized 

 of the Articulata, and possess a true muscular heart, and a 

 complicated respiratory apparatus; our little friends the 

 pycnogons have neither heart nor lungs, or at any rate no 

 special organs which arc entitled to rank as such. * • • 

 As far as my observations have gone, there appear to bo 

 two species, at least, common on this coast ; one, somewhat 

 larger than the other, is, I believe, identical with that 

 figured by Dr. Carpenter under the name of Ammothea 

 pycnogonoides; and of his woodcut the illustration is an en- 

 larged copy. The other species is, if anything.commonerthaa 

 the first, and differs in such important particulars that I have 

 no doubt it belongs to a distinct genus — though I have not yet 



