'A SAN DTEGO SOCIETY OP NATURATi HISTORY 



LINDSTROM ( G.) — Contin ued 



scarbridus Ang., S. lat'tfrons Aug., .V. lanndlm iiov., S. Bcyr'uhi nov. Vouiigia new 

 genus genotype C.lieiritnis trispinous Etlieridge and Nicholson. 



Cephalon semi-circular with long spines to the genal angles; glabella sub-circular 

 convex truncated posteriorly by occipital furrow o\'erhanging front 3 pairs of lateral 

 furrows to the glabella; occipital ring with long spine; fixed cheeks, small, short, nar- 

 row. Pygidium not known. 



The author describes as new Yoinigid i^lo/'ict'Ps and Y. inerm'n Driplion Forhesi 

 Barr. Encrniurus puncttittis W'ahlen., H. lae-vis Aug., E. ohtiisus Ang. Aciduspis 

 crenata Emm., A. Barrandei Aug., A. Mtirklirii Aug., //. pectinata Ang., A. (Trapelo- 

 cera) hicuspis Aiiglin. Lhlius loiuinnus Ang., L. latifrons Ang., L. palifer nov., L. 

 araneus nov., L. ortuitus, L. margirmtus nov., L. •vishyensis nov., L. pl'uatus nov., L. 

 iriquetrus nov., L. rotundifrons Ang., L. gotlandicux Ang. Trocliurus Salteri Fletcher. 



The generic name of Trochurus was used by Beyrich Bohm, Tril., 1845, p. 31, for 

 a composite and artificial species consisting of the head of Statirocepluiliis Murclihoni 

 and the tail of L'lchas palmuta Barr., which the author recognized in the l-ntersuch 

 uber l^ril., 1846, p. 10, and declared that tiie genus did not exist. The name was le- 

 vived by Lindstrom in a wider and slightly different sense, giving Licluis Salter} as 

 the type, including Trocliurus pusillus Ang. Harpes acuminatus nov. 



Cal}'mmene tuberculata Brunnich, C. spectablis Ang., C. laevis nov., preoccupied 

 bv Munster of a species of Calymmene which is now referred to Phacops (C. l.ind- 

 strijini uoY.) Calymmene froiitosa nov., C. intermedia nov., C. exca-vata nov., (,'. papil- 

 lata nov. Homalonotus Knighii Konig. Pliaetonides Stokesi Murch., P. rugulusus 

 nov., P. longifruns nov. ('yphaspis eleganlula Ang., C punctillosa nov. Proetus con- 

 iinnns Dalm., /-". oheonieus nov., /•". distans nov., P. aculus n(>\., P. conspersus Aug., 

 P. signatus nov., P. granulatus nov., P. verrucosus nov. lllaenus subgen. Bumastus 

 barriensis Murch., B. Holmi no\-., B. sulcatus nov. for lllaenus insignis Holm. Bronteus 

 platyactin Ang., B. Marklini Aug., B. polyaclin Aug., B. irrandians nov., H. umhoiiatus 

 nov., B. crebristriatus nov. 



Merostomer: Euryplerus Fisclien Eichw. Ptcrygotus osiliensis Schm. 



• Teher die Sehiehtenfolge des Silur des Insel Gotland. 



Neues Jahrb. Min. Geo). Pal., Bd. 1, 1888, pp. 147-164. 



KeseaiX'lies on the visual organs of the Trilobites. 



Kongl. Svenska Vetenskaps Akad. Handlingar Bandet 34, No. 8, 1901. 



Dr. Lindstrom considers certain nodes on the hypostoma to be visual organs. This 

 is based on the discovery of Dr. Liljevali from the hypostoma of Bronteus polyactin 

 Ang. They are located on the inferior edge of the upper groove, close to the lateral 

 margins. To these tubercles he gives tlic name of "maculae". The)' are oblong or 

 ellipsoid; tiieir inferior apices bkmtly pointed or roiuided, two-thirds of their surface 

 is perfectly smooth or glossy, aiul tlie lower one-third covered with a compact accumu- 

 lation of small granules, similar to the facets of the compound eyes of Trilobites. The 

 author, therefore, assumes that they are a pair of small adventive eyes on the exterior 

 side of the hypostoma, from the perfect structural agreement between them and the 

 eyes of the head. The author sums up the literature on blind trilobites without facial 

 ridge; also those with facial ridge, and il!i:strntes the maculae on the hypostoma of 

 39 genera and 136 species. 



The different genera are divided into six groups as follows: 



Group 1 — In the sectioned maculae there is no tract of any structure. The test of 

 the maculae considerably thinner than that of the hypostoma. According to tlie afiinites 

 of the genera they may be subdivided as follows, a — Bumastus, Dysplanus. b — 



