THE MOUNT DESERT REGION 95 



Skeleton. This consists of a meshwork of polyspicular 

 fibers making a fairly regular reticulum of rectangular 

 meshes. Spongin is small in amount or wanting. 



Spicules. Megascleres are stout, usually curved styli, which 

 vary from .146 to .219 mm. in length. 



Microscleres are small isochelae of the type found in the 

 genus Homeodictya and vary from .024 mm. to .028 mm. in 

 length. These isochelae are very scarce and Lambe reports 

 the same for his specimens from Vancouver Island, British 

 Columbia. 



Remarks. This specimen closely resembles Romoedictya 

 palmata except that this species has oxea instead of styli. 



Lambe has described three new species of Esperiopsis with 

 the typical Homoeodictya — chelae from the Pacific coast of 

 North America. As the species of this genus present a variety 

 of forms, the exterior appearance of these specimens cannot 

 be used as a criterion for distinguishing them. The only dif- 

 ference between them to be found in his brief descriptions is 

 the size of the spicules, and these form a so nicely graded 

 series as to make it questionable whether this character is an 

 adequate criterion for separating them. Lambe 's diagnosis 

 of these three species is tabulated below. 



There seems to be no adequate reason for separating these 

 three forms, and from their descriptions there seems to be no 

 real distinction between any of them and the form from the 

 Mount Desert Region. As the size of the spicules for the 

 specimen from this region coincides with those given for 

 Esperiopsis quatsinoensis, it has been placed in that species. 



H. V. "Wilson has described Esperiopsis obliqua from. Beau- 

 fort, North Carolina but this species has toxa as well as iso- 

 chelae. Esperiopsis forcipula has been described from Davis 

 Strait, but this species possesses forceps in addition to iso- 

 chelae. Consequently Esperiopsis quatsinoensis is not to be 

 confused with these two species. 



Greographical distribution. Vancouver Island, Straits of 

 Georgia, British Columbia; Atka Island (Aleutian Islands). 

 (Lambe) : Mount Desert Region. 



