SPONGES FROM THE AVESTEEN COAST OF NOETH AMERICA. 131 



Tlie measurements given by Carter (op. cit.) of the spicules of the type specimen from 

 the Gulf of Manaar, India, are as follows : — tylostyli(si(b-pinlike spicules) 0-18 nini. in length ; 

 sigmata {bihamate spicules) 0-102 mm. in length; foxa {tricurvate spicules) 0-Obl mm. long; 

 anisochelœ (inequianchorate spicules) 0'017 mm. long. 



The specimen first described by Carter was of very small size. That author with refer- 

 ence to his sponge says " a minute portion has grown on one of the Melobesian nodules, which 

 has yielded sufficient for mounting and retaining in the dried state respectively." " Size of 

 specimen about l-6th inch in horizontal diameter." The smallness of the type specimen 

 precluded a description of the general arrangement of the skeleton. There are no appre- 

 ciable differences to be found in the size and form of the spicules of the Vancouver specimens 

 and those of the type from the Gulf of Manaar. 



One of the four specimens collected by Prof Macoun differs slightly in spiculation from 

 the other three but not sufficiently to warrant its being regarded as specifically distinct. Its 

 sigmata are smaller (Plate IV., fig. 7e), averaging 0-065 mm. in length and are without the 

 serration at the ends. The tylostyli are shorter, varying in length from 0-314 to 0-262 mm. 

 but of about the same thickness. The toxa have a greater variation in size (Plate IV., figs. 

 7g, 7h), the largest attaining a length of 0-085 mm. The anisochehe are of the same dimen- 

 sions. The evenljM-ounded ends of the sigmata of this Vancouver specimen, however, would 

 lead one to believe that the serration of the outer curve toward the ends of these spicules, 

 the character which has evidently suggested the specific name, is not constant. 



List of localities at which specimens were collected. 

 1. arctic ocean. 



Pearl Bay.— Lat. 71° 02' N., Long, 1.57° 46' W., U. S. Revenue Steamer " Corwin," Capt. M. A. Healy commanding, 

 Aug. 24tli, 1884. 19 fathoms. 



Halichondria paiiicea. 



Myxilla Barentsi. 



Suberites concinnus. 

 Near Icy Cape.— W. H. Dall, 1880. 



Esperella helios. 



Phakellia ventilabrum. 

 Arctic Ocean. — U. S Revenue Steamer " Corwin." 



Phakellia ventilahru m, 



2. KOTZEBUE SOUND. 

 Port Clarence.— W. H. Dall, 1880. Beach. 



Reniera rufescens. 

 Myxilla Barentsi. 

 Pliakellia ventilabrum. 

 Chamisso Island.— W. H. Dall, 1880. .5-8 fathoms. 

 Reniera rufescens. 

 Phakellia ventilabrum. 



3. BEHRING STRAIT. 



Lat. 66° 45' N., Long. 166° 35' W.— W. H. Dall. 10 fathoms, sand. 



Halichondria paiiicea. 

 Lat. 66° 12' N., Long. 168° 54' W.— Lieut. Geo. M. Stoney, U. S. N., July 3, 1884. 30 fathoms. 



Halichondria panicea. 

 Lat. 65° 49' N., 169° 04' W.— U. S. Revenue Steamer " Corwin," Capt. M. A. Healy commanding, June 14th, 1884. 26 

 fathoms. 



Halichondria pan icea. 



Esperella helios. 



